// see http://www.onlineaspect.com/2007/06/08/auto-detect-a-time-zone-with-javascript/

// unfortunately, this code only tells you if a region observes DST, but doesn't have an opinion on whether it is DST now!
function calculate_time_zone() {
	var rightNow = new Date();
	var jan1 = new Date(rightNow.getFullYear(), 0, 1, 0, 0, 0, 0);  // jan 1st
	var temp = jan1.toGMTString();
	var jan2 = new Date(temp.substring(0, temp.lastIndexOf(" ")-1));
	var std_time_offset = (jan1 - jan2) / (1000 * 60 * 60);

	var june1 = new Date(rightNow.getFullYear(), 6, 1, 0, 0, 0, 0); // june 1st
	temp = june1.toGMTString();
	var june2 = new Date(temp.substring(0, temp.lastIndexOf(" ")-1));
	var daylight_time_offset = (june1 - june2) / (1000 * 60 * 60);
	var dst;
	if (std_time_offset == daylight_time_offset) {
		dst = "0"; // daylight savings time is NOT observed
	} else {
		// positive is southern, negative is northern hemisphere
		var hemisphere = std_time_offset - daylight_time_offset;
		if (hemisphere >= 0) {
			std_time_offset = daylight_time_offset;
		}
		dst = "1"; // daylight savings time is observed
	}

	return parseInt(std_time_offset) + parseInt(dst);

}

$(document).ready(function() {
  var now = new Date()
  $('input[id="UserTzOffset"]').val(-(now.getTimezoneOffset()/60));

//	offset_now();
//	$('input[id="UserTzOffset"]').val(calculate_time_zone());
});