How to check if DST (Daylight Saving Time) is in effect, and if so, the offset?

Question

This is a bit of my JS code for which this is needed:

var secDiff = Math.abs(Math.round((utc_date-this.premiere_date)/1000));
this.years = this.calculateUnit         


        

Answer 1

I was faced with this same problem today but since our daylight saving starts and stops at differing times from the USA (at least from my understanding), I used a slightly different route..

var arr = [];
for (var i = 0; i < 365; i++) {
 var d = new Date();
 d.setDate(i);
 newoffset = d.getTimezoneOffset();
 arr.push(newoffset);
}
DST = Math.min.apply(null, arr);
nonDST = Math.max.apply(null, arr);

Then you simply compare the current timezone offset with DST and nonDST to see which one matches.