Javascript countdown using absolute timezone?

Question

I have a javascript countdown timer that works by taking a specified date and time, and comparing it to the current date and time. The issue is, the current time is relative

Answer 1

To revise the approach Brandon has taken to calculate a UTC-shifted time, we can slim the code down into a two-line extension of the Date object:

/* getOffsetDate - Returns a Date shifted by a certain offset 
 * @param offset the UTC offset to shift, in hours
 * @return new date object shifted by UTC offset
 */
Date.prototype.getOffsetDate = function( offset ) {
  utc = this.getTime() + (this.getTimezoneOffset() * 60000);
  return new Date(utc + (3600000*offset));
}

You can then calculate the UTC-5 shifted date as follows:

myDate = new Date().getOffsetDate(-5); 

It should be noted that extending native prototypes in this manner is generally considered a bad practice since it muddles core objects that other libraries depend upon. To justify it, you'd have to argue this functionality should be a native part of the Date object.