WallTimeToUTC

Converts a datetime from a specified timezone to UTC.

Signature 

WallTimeToUTC (Date date, string timezone, function callback)

Parameters 

date: Type: Date. A JavaScript Date object.

timezone: Type: String. A time zone ID based on the “ class, for example, "America/Los_Angeles".

callback

Type: function

A function to call after the conversion is done. Access the converted value in the first parameter of the callback.