[Javascript] Date Function

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Date Function Description:
These functions are very useful when dealing with any type of date fields.
They use the same format strings as the java.text.SimpleDateFormat class, with a few minor exceptions.
Functions include:

• isDate() - Check if a date is valid
• compareDates() - See if one date is greater than another
• formatDate() - Output a Date() object in any format
• getDateFromFormat() - Parse a date string and return time in ms representing date object

Reference : Date Functions