instance method Date#toISOString
Date#toISOString() → String
Produces a string representation of the date in ISO 8601 format. The time zone is always UTC, as denoted by the suffix "Z".
Example
var d = new Date(1969, 11, 31, 19); d.getTimezoneOffset(); //-> -180 (time offest is given in minutes.) d.toISOString(); //-> '1969-12-31T16:00:00Z'