Very tiny utility for date manipulation.

lang-date.js

/**
 * Sample:
 *   new Date().add( 20, Date.DAY ) // will point to 20 ahead from today
 *   new Date().add( -20, Date.DAY ) // will point to 20 ago from today
 */
Date.SECOND = 1000
Date.MINUTE = (60*Date.SECOND)
Date.HOUR = (60*Date.MINUTE)
Date.DAY = (24*Date.HOUR)

Date.prototype.add = function( size, unit ){
	unit = unit || Date.SECOND
	size = size || 0
	return new Date( this.getTime() + (size*unit) )
}