This library is based on moment.js; and now have the following client actions with localization in many languages.

momentAdd

input: referenceDateTime, Unit, Value

output: DateTime

Returns the original moment by adding Value by Unit.
This is a pretty robust function for adding time to an existing moment. To add time, pass the key of what time you want to add, and the amount you want to add. For example MonmentAdd( CurrDateTime() 'year', 10) returns today + 10 years.

momentCalendar 

input: referenceDate, Locale 

output: Text

Will format a date with different strings depending on how close to referenceDate (today by default) the date is.

momentDiff

input: referenceDateTime1, referenceDateTime1, Unit, WithFractions, Value

output: Integer

Returns the Duration in Unit (year, month, week, day) between referenceDateTime1 and referenceDateTime2

momentEndOf

input: referenceDateTime, Unit

output: DateTime

Returns the EndOf a given period (unit, (year, quarter, month, week, day).

momentFormat

input: referenceDateTime, Format, Locale

output: Text

Returns the referenceDateTime in given Format and Locale, for example

MomentFormat(#2019-06-04 01:42#, "LLLL", "de") returns 'Freitag, 24. Juni 2016 01:42'

Go to the Moment JS website for the full description of the format / parsing a string with localization.

momentStartOf

input: referenceDateTime, Unit

output: DateTime  

Returns the StartOf a given period (unit, (year, quarter, month, week, day).

momentSubstract

input: referenceDateTime, Unit, Value

output: DateTime

Returns the original moment by substracting Value by Unit.
This is a pretty robust function for adding time to an existing moment. To add time, pass the key of what time you want to add, and the amount you want to add. For example MonmentAdd( CurrDateTime() 'year', 10) returns today - 10 years.

momentWeekDay_Date

input: referenceDateTime, daynumber, locale

output: Value

This method can be used to get the date for  the daynumber week of referenceDateTime

momentWeekDay_Number

input: referenceDateTime, locale

output: Value

This method can be used to get the day of the week, with Sunday as 0 and Saturday as 6.

For full documentation of this javascript library go to the project website https://momentjs.com