function checkTimeZone() {
   var rightNow = new Date();
   var date1 = new Date(rightNow.getFullYear(), 0, 1, 0, 0, 0, 0);
   var date2 = new Date(rightNow.getFullYear(), 6, 1, 0, 0, 0, 0);
   var temp = date1.toGMTString();
   var date3 = new Date(temp.substring(0, temp.lastIndexOf(" ")-1));
   var temp = date2.toGMTString();
   var date4 = new Date(temp.substring(0, temp.lastIndexOf(" ")-1));
   var hoursDiffStdTime = (date1 - date3) / (1000 * 60 * 60);
   var hoursDiffDaylightTime = (date2 - date4) / (1000 * 60 * 60);
   /*if (hoursDiffDaylightTime == hoursDiffStdTime) { 
      alert("Time zone is GMT " + hoursDiffStdTime + ".\nDaylight Saving Time is NOT observed here.");
   } else {
      alert("Time zone is GMT " + hoursDiffStdTime + ".\nDaylight Saving Time is observed here.");
   }*/
   if(document.getElementById('txtUTCOffset')){
    document.getElementById('txtUTCOffset').value = hoursDiffStdTime;
   }
   //offset of -8 = PST (our server)
    //deleteCookie('hoursDiffStdTime', hoursDiffStdTime, 0);
    createCookie('hoursDiffStdTime', hoursDiffStdTime, 0); 

}

function createCookie(name,value,days) {

if (days && days > 0) {

var date = new Date();

date.setTime(date.getTime()+(days*24*60*60*1000));

var expires = "; expires="+date.toGMTString();

}

else var expires = "";

document.cookie = name+"="+value+expires+"; path=/";

}

function openVCalendar(url){
    var UTCOffset = document.getElementById('txtUTCOffset').value;
    url += '&utcOffset=' + UTCOffset;
    window.open(url,'vCal','');
}
checkTimeZone();