Changed to use double values ands only perform a single pass through …

…the relationship list.

docs/datetime.adoc

@@ -15,6 +15,18 @@ endif::env-guide[]
 * possible unit values: `ms,s,m,h,d` and their long forms.
 * possible time zone values: Either an abbreviation such as `PST`, a full name such as `America/Los_Angeles`, or a custom ID such as `GMT-8:00`. Full names are recommended.
 
+== Conversion of timestamps between different time units
+
+* `apoc.date.convert(12345, 'ms', 'd')` convert a timestamp in one time unit into one of a different time unit
+
+* possible unit values: `ms,s,m,h,d` and their long forms.
+
+== Adding/subtracting time unit values to timestamps
+
+* `apoc.date.add(12345, 'ms', -365, 'd')` given a timestamp in one time unit, adds a value of the specified time unit
+
+* possible unit values: `ms,s,m,h,d` and their long forms.
+
 == Reading separate datetime fields:
 
 Splits date (optionally, using given custom format) into fields returning a map from field name to its value.

docs/overview.adoc

@@ -805,6 +805,18 @@ Optionally set `apoc.ttl.schedule=5` as repeat frequency.
 * possible unit values: `ms,s,m,h,d` and their long forms `millis,milliseconds,seconds,minutes,hours,days`.
 * possible time zone values: Either an abbreviation such as `PST`, a full name such as `America/Los_Angeles`, or a custom ID such as `GMT-8:00`. Full names are recommended. You can view a list of full names in https://en.wikipedia.org/wiki/List_of_tz_database_time_zones[this Wikipedia page].
 
+=== Conversion of timestamps between different time units
+
+* `apoc.date.convert(12345, 'ms', 'd')` convert a timestamp in one time unit into one of a different time unit
+
+* possible unit values: `ms,s,m,h,d` and their long forms.
+
+=== Adding/subtracting time unit values to timestamps
+
+* `apoc.date.add(12345, 'ms', -365, 'd')` given a timestamp in one time unit, adds a value of the specified time unit
+
+* possible unit values: `ms,s,m,h,d` and their long forms.
+
 === Reading separate datetime fields
 
 Splits date (optionally, using given custom format) into fields returning a map from field name to its value.

src/main/java/apoc/date/Date.java

@@ -137,13 +137,13 @@ public String systemTimezone() {
 	}
 
 	@UserFunction
-	@Description("apoc.date.convert(12345,'ms|s|m|h|d','ms|s|m|h|d') convert a time unit into a different time unit")
+	@Description("apoc.date.convert(12345, 'ms', 'd') convert a timestamp in one time unit into one of a different time unit")
 	public Long convert(@Name("time") long time, @Name(value = "unit") String unit, @Name(value = "toUnit") String toUnit) {
 		return unit(toUnit).convert(time, unit(unit));
 	}
 
 	@UserFunction
-	@Description("apoc.date.add(12345,'ms|s|m|h|d', 54321, 'ms|s|m|h|d') adds a value of the specified time unit to the original value, outputing in the original value's time unit")
+	@Description("apoc.date.add(12345, 'ms', -365, 'd') given a timestamp in one time unit, adds a value of the specified time unit")
 	public Long add(@Name("time") long time, @Name(value = "unit") String unit, @Name(value = "addValue") long addValue, @Name(value = "addUnit") String addUnit) {
 		long valueToAdd = unit(unit).convert(addValue, unit(addUnit));
 		return time + valueToAdd;