From 0184842b09748b805d87c7bd8f87e7e88b1f4944 Mon Sep 17 00:00:00 2001
From: Philip Chimento <philip.chimento@gmail.com>
Date: Mon, 18 Oct 2021 14:16:28 -0700
Subject: [PATCH] Test rejection of "Z" UTC designators in Plain strings

Tests for the normative changes made to Temporal in
https://github.com/tc39/proposal-temporal/pull/1874
---
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 27 +++++++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 26 ++++++++++++++++++
 .../argument-string-with-utc-designator.js    | 20 ++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 26 ++++++++++++++++++
 .../argument-string-with-utc-designator.js    | 20 ++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 20 ++++++++++++++
 .../PlainMonthDay/from/fields-string.js       |  3 +--
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 26 ++++++++++++++++++
 .../argument-string-with-utc-designator.js    | 20 ++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 26 ++++++++++++++++++
 .../argument-string-with-utc-designator.js    | 20 ++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 .../argument-string-with-utc-designator.js    | 21 +++++++++++++++
 49 files changed, 1030 insertions(+), 2 deletions(-)
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/dateAdd/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/dateUntil/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/day/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/dayOfWeek/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/dayOfYear/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/daysInMonth/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/daysInWeek/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/daysInYear/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/inLeapYear/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/month/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/monthCode/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/monthsInYear/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/weekOfYear/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/Calendar/prototype/year/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDate/compare/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDate/from/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDate/prototype/equals/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDate/prototype/since/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDate/prototype/toPlainDateTime/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDate/prototype/toZonedDateTime/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDate/prototype/until/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDateTime/compare/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDateTime/from/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDateTime/prototype/since/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDateTime/prototype/until/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDateTime/prototype/withPlainDate/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainDateTime/prototype/withPlainTime/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainMonthDay/from/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainMonthDay/prototype/equals/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainTime/compare/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainTime/from/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainTime/prototype/equals/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainTime/prototype/since/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainTime/prototype/toPlainDateTime/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainTime/prototype/toZonedDateTime/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainTime/prototype/until/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainYearMonth/compare/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainYearMonth/from/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainYearMonth/prototype/equals/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainYearMonth/prototype/since/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/PlainYearMonth/prototype/until/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/TimeZone/prototype/getInstantFor/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/TimeZone/prototype/getPossibleInstantsFor/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/ZonedDateTime/prototype/withPlainDate/argument-string-with-utc-designator.js
 create mode 100644 test/built-ins/Temporal/ZonedDateTime/prototype/withPlainTime/argument-string-with-utc-designator.js
 create mode 100644 test/intl402/Temporal/Calendar/prototype/era/argument-string-with-utc-designator.js
 create mode 100644 test/intl402/Temporal/Calendar/prototype/eraYear/argument-string-with-utc-designator.js

diff --git a/test/built-ins/Temporal/Calendar/prototype/dateAdd/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/dateAdd/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..6c60a8c4b8a
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/dateAdd/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.dateadd
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.dateAdd(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/dateUntil/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/dateUntil/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..8aa77d5e756
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/dateUntil/argument-string-with-utc-designator.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.dateuntil
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+const plainDate = new Temporal.PlainDate(2000, 5, 2);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.dateUntil(arg, plainDate),
+    "String with UTC designator should not be valid as a PlainDate (first argument)"
+  );
+  assert.throws(
+    RangeError,
+    () => instance.dateUntil(plainDate, arg),
+    "String with UTC designator should not be valid as a PlainDate (second argument)"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/day/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/day/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..04a1a7af9cc
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/day/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.day
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.day(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/dayOfWeek/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/dayOfWeek/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..03e1b79e161
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/dayOfWeek/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.dayofweek
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.dayOfWeek(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/dayOfYear/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/dayOfYear/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..9a9a64034da
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/dayOfYear/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.dayofyear
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.dayOfYear(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/daysInMonth/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/daysInMonth/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..c0c1db53d34
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/daysInMonth/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.daysinmonth
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.daysInMonth(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/daysInWeek/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/daysInWeek/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..3db13fecb3a
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/daysInWeek/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.daysinweek
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.daysInWeek(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/daysInYear/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/daysInYear/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..b19041f274a
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/daysInYear/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.daysinyear
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.daysInYear(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/inLeapYear/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/inLeapYear/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..a4ef7f78a37
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/inLeapYear/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.inleapyear
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.inLeapYear(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/month/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/month/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..874d8969a41
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/month/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.month
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.month(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/monthCode/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/monthCode/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..36e61a87351
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/monthCode/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.monthcode
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.monthCode(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/monthsInYear/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/monthsInYear/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..6525702930c
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/monthsInYear/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.monthsinyear
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.monthsInYear(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/weekOfYear/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/weekOfYear/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..65513108298
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/weekOfYear/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.weekofyear
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.weekOfYear(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/Calendar/prototype/year/argument-string-with-utc-designator.js b/test/built-ins/Temporal/Calendar/prototype/year/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..5d8a8c91c72
--- /dev/null
+++ b/test/built-ins/Temporal/Calendar/prototype/year/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.year
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.year(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDate/compare/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDate/compare/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..4e5adcda0e9
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDate/compare/argument-string-with-utc-designator.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.compare
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const plainDate = new Temporal.PlainDate(2000, 5, 2);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainDate.compare(arg, plainDate),
+    "String with UTC designator should not be valid as a PlainDate (first argument)"
+  );
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainDate.compare(plainDate, arg),
+    "String with UTC designator should not be valid as a PlainDate (second argument)"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDate/from/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDate/from/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..10fa5a31263
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDate/from/argument-string-with-utc-designator.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.from
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainDate.from(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDate/prototype/equals/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDate/prototype/equals/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..ce6eb2c9f04
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDate/prototype/equals/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.equals
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainDate(2000, 5, 2);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.equals(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDate/prototype/since/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDate/prototype/since/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..cac649374f9
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDate/prototype/since/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.since
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainDate(2000, 5, 2);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.since(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDate/prototype/toPlainDateTime/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDate/prototype/toPlainDateTime/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..65c1bc1c82a
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDate/prototype/toPlainDateTime/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.toplaindatetime
+description: RangeError thrown if a string with UTC designator is used as a PlainTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainDate(2000, 5, 2);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.toPlainDateTime(arg),
+    "String with UTC designator should not be valid as a PlainTime"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDate/prototype/toZonedDateTime/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDate/prototype/toZonedDateTime/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..ee1fa639c02
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDate/prototype/toZonedDateTime/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.tozoneddatetime
+description: RangeError thrown if a string with UTC designator is used as a PlainTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainDate(2000, 5, 2);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.toZonedDateTime({ plainTime: arg, timeZone: "UTC" }),
+    "String with UTC designator should not be valid as a PlainTime"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDate/prototype/until/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDate/prototype/until/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..6b6198c8770
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDate/prototype/until/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.until
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainDate(2000, 5, 2);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.until(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDateTime/compare/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDateTime/compare/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..696793495b3
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDateTime/compare/argument-string-with-utc-designator.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.compare
+description: RangeError thrown if a string with UTC designator is used as a PlainDateTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const dateTime = new Temporal.PlainDateTime(2000, 5, 2);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainDateTime.compare(arg, dateTime),
+    "String with UTC designator should not be valid as a PlainDateTime (first argument)"
+  );
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainDateTime.compare(arg, dateTime),
+    "String with UTC designator should not be valid as a PlainDateTime (second argument)"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDateTime/from/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDateTime/from/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..bb4495586d7
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDateTime/from/argument-string-with-utc-designator.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.from
+description: RangeError thrown if a string with UTC designator is used as a PlainDateTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainDateTime.from(arg),
+    "String with UTC designator should not be valid as a PlainDateTime"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..b5e50fab421
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.equals
+description: RangeError thrown if a string with UTC designator is used as a PlainDateTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainDateTime(2000, 5, 2, 12, 34, 56, 987, 654, 321);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.equals(arg),
+    "String with UTC designator should not be valid as a PlainDateTime"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDateTime/prototype/since/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDateTime/prototype/since/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..f2ec0252b64
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDateTime/prototype/since/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.since
+description: RangeError thrown if a string with UTC designator is used as a PlainDateTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainDateTime(2000, 5, 2, 12, 34, 56, 987, 654, 321);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.since(arg),
+    "String with UTC designator should not be valid as a PlainDateTime"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDateTime/prototype/until/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDateTime/prototype/until/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..1964e576c16
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDateTime/prototype/until/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.until
+description: RangeError thrown if a string with UTC designator is used as a PlainDateTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainDateTime(2000, 5, 2, 12, 34, 56, 987, 654, 321);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.until(arg),
+    "String with UTC designator should not be valid as a PlainDateTime"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDateTime/prototype/withPlainDate/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDateTime/prototype/withPlainDate/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..1e7bb2021b4
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDateTime/prototype/withPlainDate/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.withplaindate
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainDateTime(2000, 5, 2, 12, 34, 56, 987, 654, 321);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.withPlainDate(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainDateTime/prototype/withPlainTime/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainDateTime/prototype/withPlainTime/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..80baeb2ea52
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDateTime/prototype/withPlainTime/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.withplaintime
+description: RangeError thrown if a string with UTC designator is used as a PlainTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainDateTime(2000, 5, 2, 12, 34, 56, 987, 654, 321);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.withPlainTime(arg),
+    "String with UTC designator should not be valid as a PlainTime"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainMonthDay/from/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainMonthDay/from/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..a02040a02a0
--- /dev/null
+++ b/test/built-ins/Temporal/PlainMonthDay/from/argument-string-with-utc-designator.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plainmonthday.from
+description: RangeError thrown if a string with UTC designator is used as a PlainMonthDay
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainMonthDay.from(arg),
+    "String with UTC designator should not be valid as a PlainMonthDay"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainMonthDay/from/fields-string.js b/test/built-ins/Temporal/PlainMonthDay/from/fields-string.js
index 618e654049b..8386dcd1cbd 100644
--- a/test/built-ins/Temporal/PlainMonthDay/from/fields-string.js
+++ b/test/built-ins/Temporal/PlainMonthDay/from/fields-string.js
@@ -12,8 +12,6 @@ const tests = [
   "10-01",
   "1001",
   "1965-10-01",
-  "2019-10-01T09:00:00Z",
-  "2019-10-01T00:00:00Z",
   "1976-10-01T152330.1+00:00",
   "19761001T15:23:30.1+00:00",
   "1976-10-01T15:23:30.1+0000",
@@ -28,6 +26,7 @@ const tests = [
   "+0019761001T15:23:30.1+0000",
   "+0019761001T152330.1+00:00",
   "+0019761001T152330.1+0000",
+  "1976-10-01T15:23:00",
   "1976-10-01T15:23",
   "1976-10-01T15",
   "1976-10-01",
diff --git a/test/built-ins/Temporal/PlainMonthDay/prototype/equals/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainMonthDay/prototype/equals/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..c022733553e
--- /dev/null
+++ b/test/built-ins/Temporal/PlainMonthDay/prototype/equals/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plainmonthday.prototype.equals
+description: RangeError thrown if a string with UTC designator is used as a PlainMonthDay
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainMonthDay(5, 2);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.equals(arg),
+    "String with UTC designator should not be valid as a PlainMonthDay"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainTime/compare/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainTime/compare/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..61b28a61f59
--- /dev/null
+++ b/test/built-ins/Temporal/PlainTime/compare/argument-string-with-utc-designator.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaintime.compare
+description: RangeError thrown if a string with UTC designator is used as a PlainTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const plainTime = new Temporal.PlainTime();
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainTime.compare(arg, plainTime),
+    "String with UTC designator should not be valid as a PlainTime (first argument)"
+  );
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainTime.compare(plainTime, arg),
+    "String with UTC designator should not be valid as a PlainTime (second argument)"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainTime/from/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainTime/from/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..70e7b22506b
--- /dev/null
+++ b/test/built-ins/Temporal/PlainTime/from/argument-string-with-utc-designator.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaintime.from
+description: RangeError thrown if a string with UTC designator is used as a PlainTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainTime.from(arg),
+    "String with UTC designator should not be valid as a PlainTime"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainTime/prototype/equals/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainTime/prototype/equals/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..8ea64a6f57f
--- /dev/null
+++ b/test/built-ins/Temporal/PlainTime/prototype/equals/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaintime.prototype.equals
+description: RangeError thrown if a string with UTC designator is used as a PlainTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainTime(12, 34, 56, 987, 654, 321);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.equals(arg),
+    "String with UTC designator should not be valid as a PlainTime"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainTime/prototype/since/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainTime/prototype/since/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..ccc946fbc56
--- /dev/null
+++ b/test/built-ins/Temporal/PlainTime/prototype/since/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaintime.prototype.since
+description: RangeError thrown if a string with UTC designator is used as a PlainTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainTime(12, 34, 56, 987, 654, 321);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.since(arg),
+    "String with UTC designator should not be valid as a PlainTime"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainTime/prototype/toPlainDateTime/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainTime/prototype/toPlainDateTime/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..eae48d0ee22
--- /dev/null
+++ b/test/built-ins/Temporal/PlainTime/prototype/toPlainDateTime/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaintime.prototype.toplaindatetime
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainTime(12, 34, 56, 987, 654, 321);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.toPlainDateTime(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainTime/prototype/toZonedDateTime/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainTime/prototype/toZonedDateTime/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..7af7b65a9a5
--- /dev/null
+++ b/test/built-ins/Temporal/PlainTime/prototype/toZonedDateTime/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaintime.prototype.tozoneddatetime
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainTime(12, 34, 56, 987, 654, 321);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.toZonedDateTime({ plainDate: arg }),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainTime/prototype/until/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainTime/prototype/until/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..a64138a1a1e
--- /dev/null
+++ b/test/built-ins/Temporal/PlainTime/prototype/until/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaintime.prototype.until
+description: RangeError thrown if a string with UTC designator is used as a PlainTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainTime(12, 34, 56, 987, 654, 321);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.until(arg),
+    "String with UTC designator should not be valid as a PlainTime"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainYearMonth/compare/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainYearMonth/compare/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..d1bd7ab5253
--- /dev/null
+++ b/test/built-ins/Temporal/PlainYearMonth/compare/argument-string-with-utc-designator.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plainyearmonth.compare
+description: RangeError thrown if a string with UTC designator is used as a PlainYearMonth
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const yearMonth = new Temporal.PlainYearMonth(2000, 5);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainYearMonth.compare(arg, yearMonth),
+    "String with UTC designator should not be valid as a PlainYearMonth (first argument)"
+  );
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainYearMonth.compare(yearMonth, arg),
+    "String with UTC designator should not be valid as a PlainYearMonth (second argument)"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainYearMonth/from/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainYearMonth/from/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..96aa55f278f
--- /dev/null
+++ b/test/built-ins/Temporal/PlainYearMonth/from/argument-string-with-utc-designator.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plainyearmonth.from
+description: RangeError thrown if a string with UTC designator is used as a PlainYearMonth
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => Temporal.PlainYearMonth.from(arg),
+    "String with UTC designator should not be valid as a PlainYearMonth"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainYearMonth/prototype/equals/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainYearMonth/prototype/equals/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..a98dd0f502f
--- /dev/null
+++ b/test/built-ins/Temporal/PlainYearMonth/prototype/equals/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plainyearmonth.prototype.equals
+description: RangeError thrown if a string with UTC designator is used as a PlainYearMonth
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainYearMonth(2000, 5);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.equals(arg),
+    "String with UTC designator should not be valid as a PlainYearMonth"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainYearMonth/prototype/since/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainYearMonth/prototype/since/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..0ad1f56edbb
--- /dev/null
+++ b/test/built-ins/Temporal/PlainYearMonth/prototype/since/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plainyearmonth.prototype.since
+description: RangeError thrown if a string with UTC designator is used as a PlainYearMonth
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainYearMonth(2000, 5);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.since(arg),
+    "String with UTC designator should not be valid as a PlainYearMonth"
+  );
+});
diff --git a/test/built-ins/Temporal/PlainYearMonth/prototype/until/argument-string-with-utc-designator.js b/test/built-ins/Temporal/PlainYearMonth/prototype/until/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..1fab4ff184d
--- /dev/null
+++ b/test/built-ins/Temporal/PlainYearMonth/prototype/until/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plainyearmonth.prototype.until
+description: RangeError thrown if a string with UTC designator is used as a PlainYearMonth
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.PlainYearMonth(2000, 5);
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.until(arg),
+    "String with UTC designator should not be valid as a PlainYearMonth"
+  );
+});
diff --git a/test/built-ins/Temporal/TimeZone/prototype/getInstantFor/argument-string-with-utc-designator.js b/test/built-ins/Temporal/TimeZone/prototype/getInstantFor/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..d607c549b08
--- /dev/null
+++ b/test/built-ins/Temporal/TimeZone/prototype/getInstantFor/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.timezone.prototype.getinstantfor
+description: RangeError thrown if a string with UTC designator is used as a PlainDateTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.TimeZone("UTC");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.getInstantFor(arg),
+    "String with UTC designator should not be valid as a PlainDateTime"
+  );
+});
diff --git a/test/built-ins/Temporal/TimeZone/prototype/getPossibleInstantsFor/argument-string-with-utc-designator.js b/test/built-ins/Temporal/TimeZone/prototype/getPossibleInstantsFor/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..c6032d465ba
--- /dev/null
+++ b/test/built-ins/Temporal/TimeZone/prototype/getPossibleInstantsFor/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.timezone.prototype.getpossibleinstantsfor
+description: RangeError thrown if a string with UTC designator is used as a PlainDateTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.TimeZone("UTC");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.getPossibleInstantsFor(arg),
+    "String with UTC designator should not be valid as a PlainDateTime"
+  );
+});
diff --git a/test/built-ins/Temporal/ZonedDateTime/prototype/withPlainDate/argument-string-with-utc-designator.js b/test/built-ins/Temporal/ZonedDateTime/prototype/withPlainDate/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..19b30f77335
--- /dev/null
+++ b/test/built-ins/Temporal/ZonedDateTime/prototype/withPlainDate/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.withplaindate
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.ZonedDateTime(1_000_000_000_000_000_000n, "UTC");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.withPlainDate(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/built-ins/Temporal/ZonedDateTime/prototype/withPlainTime/argument-string-with-utc-designator.js b/test/built-ins/Temporal/ZonedDateTime/prototype/withPlainTime/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..f821197cc46
--- /dev/null
+++ b/test/built-ins/Temporal/ZonedDateTime/prototype/withPlainTime/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.withplaintime
+description: RangeError thrown if a string with UTC designator is used as a PlainTime
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.ZonedDateTime(1_000_000_000_000_000_000n, "UTC");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.withPlainTime(arg),
+    "String with UTC designator should not be valid as a PlainTime"
+  );
+});
diff --git a/test/intl402/Temporal/Calendar/prototype/era/argument-string-with-utc-designator.js b/test/intl402/Temporal/Calendar/prototype/era/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..4ad95a15f89
--- /dev/null
+++ b/test/intl402/Temporal/Calendar/prototype/era/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.era
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.era(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});
diff --git a/test/intl402/Temporal/Calendar/prototype/eraYear/argument-string-with-utc-designator.js b/test/intl402/Temporal/Calendar/prototype/eraYear/argument-string-with-utc-designator.js
new file mode 100644
index 00000000000..a02303876a9
--- /dev/null
+++ b/test/intl402/Temporal/Calendar/prototype/eraYear/argument-string-with-utc-designator.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.erayear
+description: RangeError thrown if a string with UTC designator is used as a PlainDate
+features: [Temporal, arrow-function]
+---*/
+
+const invalidStrings = [
+  "2019-10-01T09:00:00Z",
+  "2019-10-01T09:00:00Z[UTC]",
+];
+const instance = new Temporal.Calendar("iso8601");
+invalidStrings.forEach((arg) => {
+  assert.throws(
+    RangeError,
+    () => instance.eraYear(arg),
+    "String with UTC designator should not be valid as a PlainDate"
+  );
+});