diff --git a/expression/builtin_time.go b/expression/builtin_time.go
index 9f4cf3e5e6793..0551f3a5e7975 100644
--- a/expression/builtin_time.go
+++ b/expression/builtin_time.go
@@ -5710,7 +5710,13 @@ func (b *builtinConvertTzSig) convertTz(dt types.Time, fromTzStr, toTzStr string
 			return types.ZeroTime, true, nil
 		}
 
+<<<<<<< HEAD
 		return types.NewTime(types.FromGoTime(t.In(toTz)), mysql.TypeDatetime, int8(b.tp.Decimal)), false, nil
+=======
+	t, err := dt.AdjustedGoTime(fromTz)
+	if err != nil {
+		return types.ZeroTime, true, nil
+>>>>>>> 8d5328ec4... expression: adjust DST for convert_tz() (#37206)
 	}
 	if fromTzMatched && toTzMatched {
 		t, err := dt.GoTime(time.Local)
diff --git a/expression/builtin_time_test.go b/expression/builtin_time_test.go
index 16fcaa8fbfaa9..8e209f934d79d 100644
--- a/expression/builtin_time_test.go
+++ b/expression/builtin_time_test.go
@@ -2637,6 +2637,28 @@ func (s *testEvaluatorSuite) TestConvertTz(c *C) {
 		{nil, "GMT", "+00:00", true, ""},
 		{"2004-01-01 12:00:00", nil, "+00:00", true, ""},
 		{"2004-01-01 12:00:00", "GMT", nil, true, ""},
+<<<<<<< HEAD
+=======
+		{"2004-01-01 12:00:00", "GMT", "+10:00", true, "2004-01-01 22:00:00"},
+		{"2004-01-01 12:00:00", "+00:00", "MET", true, "2004-01-01 13:00:00"},
+		{"2004-01-01 12:00:00", "+00:00", "+14:00", true, "2004-01-02 02:00:00"},
+		{"2021-10-31 02:59:59", "+02:00", "Europe/Amsterdam", true, "2021-10-31 02:59:59"},
+		{"2021-10-31 03:00:00", "+01:00", "Europe/Amsterdam", true, "2021-10-31 03:00:00"},
+		{"2021-10-31 02:00:00", "+02:00", "Europe/Amsterdam", true, "2021-10-31 02:00:00"},
+		{"2021-10-31 02:59:59", "+02:00", "Europe/Amsterdam", true, "2021-10-31 02:59:59"},
+		{"2021-10-31 03:00:00", "+02:00", "Europe/Amsterdam", true, "2021-10-31 02:00:00"},
+		{"2021-10-31 02:30:00", "+01:00", "Europe/Amsterdam", true, "2021-10-31 02:30:00"},
+		{"2021-10-31 03:00:00", "+01:00", "Europe/Amsterdam", true, "2021-10-31 03:00:00"},
+		// Europe/Amsterdam during DST transition +02:00 -> +01:00, Summer to normal time,
+		// will be interpreted as +01:00, normal time.
+		{"2021-10-31 02:00:00", "Europe/Amsterdam", "+02:00", true, "2021-10-31 03:00:00"},
+		{"2021-10-31 02:59:59", "Europe/Amsterdam", "+02:00", true, "2021-10-31 03:59:59"},
+		{"2021-10-31 02:00:00", "Europe/Amsterdam", "+01:00", true, "2021-10-31 02:00:00"},
+		{"2021-10-31 03:00:00", "Europe/Amsterdam", "+01:00", true, "2021-10-31 03:00:00"},
+		{"2021-03-28 02:30:00", "Europe/Amsterdam", "UTC", true, "2021-03-28 01:00:00"},
+		{"2021-10-22 10:00:00", "Europe/Tallinn", "SYSTEM", true, t1.In(loc2).Format("2006-01-02 15:04:00")},
+		{"2021-10-22 10:00:00", "SYSTEM", "Europe/Tallinn", true, t2.In(loc1).Format("2006-01-02 15:04:00")},
+>>>>>>> 8d5328ec4... expression: adjust DST for convert_tz() (#37206)
 	}
 	fc := funcs[ast.ConvertTz]
 	for _, test := range tests {
diff --git a/expression/integration_test.go b/expression/integration_test.go
index 2a6b74b291fb5..88cbb2981c8a4 100755
--- a/expression/integration_test.go
+++ b/expression/integration_test.go
@@ -8507,7 +8507,54 @@ func (s *testIntegrationSuite) TestControlFunctionWithEnumOrSet(c *C) {
 	tk.MustQuery("select * from e where if(e>2,e,e) and (if(e<3,0,e) or if(e>=2,0,e));").Sort().Check(
 		testkit.Rows("a", "a"))
 
+<<<<<<< HEAD
 	// issue 24494
+=======
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t1;")
+	tk.MustExec("create table t1(c1 bigint unsigned, c2 bigint unsigned);")
+	tk.MustExec("insert into t1 values(9223372036854775808, 9223372036854775809);")
+	tk.MustQuery("select greatest(c1, c2) from t1;").Sort().Check(testkit.Rows("9223372036854775809"))
+}
+
+func TestIssue28739(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`USE test`)
+	tk.MustExec("SET time_zone = 'Europe/Vilnius'")
+	tk.MustQuery("SELECT UNIX_TIMESTAMP('2020-03-29 03:45:00')").Check(testkit.Rows("1585443600"))
+	tk.MustQuery("SELECT FROM_UNIXTIME(UNIX_TIMESTAMP('2020-03-29 03:45:00'))").Check(testkit.Rows("2020-03-29 04:00:00"))
+	tk.MustExec(`DROP TABLE IF EXISTS t`)
+	tk.MustExec(`CREATE TABLE t (dt DATETIME NULL)`)
+	defer tk.MustExec(`DROP TABLE t`)
+	// Test the vector implememtation
+	tk.MustExec(`INSERT INTO t VALUES ('2021-10-31 02:30:00'), ('2021-03-28 02:30:00'), ('2020-10-04 02:15:00'), ('2020-03-29 03:45:00'), (NULL)`)
+	tk.MustQuery(`SELECT dt, UNIX_TIMESTAMP(dt) FROM t`).Sort().Check(testkit.Rows(
+		"2020-03-29 03:45:00 1585443600",
+		"2020-10-04 02:15:00 1601766900",
+		"2021-03-28 02:30:00 1616891400",
+		"2021-10-31 02:30:00 1635636600",
+		"<nil> <nil>"))
+}
+
+func TestIssue30081(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`USE test`)
+	tk.MustQuery(`SELECT CONVERT_TZ('2007-03-11 2:00:00','US/Eastern','US/Central');`).
+		Check(testkit.Rows(`2007-03-11 01:00:00`))
+	tk.MustQuery(`SELECT CONVERT_TZ('2007-03-11 3:00:00','US/Eastern','US/Central');`).
+		Check(testkit.Rows(`2007-03-11 01:00:00`))
+}
+
+func TestIssue30326(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+>>>>>>> 8d5328ec4... expression: adjust DST for convert_tz() (#37206)
 	tk.MustExec("drop table if exists t;")
 	tk.MustExec("create table t(a int,b enum(\"b\",\"y\",\"1\"));")
 	tk.MustExec("insert into t values(0,\"y\"),(1,\"b\"),(null,null),(2,\"1\");")