Detect timezone abbreviation using JavaScript

Question

I need a way to detect the timezone of a given date object. I do NOT want the offset, nor do I want the full timezone name. I need to get the timezone abbreviation.

Answer 1

This works perfectly in Chrome, Firefox but only mostly in IE11. In IE11, timezones without straight forward abbreviations like "Indian Chagos Time" will return "ICT" instead of the proper "IOT"

var result = "unknown";
try{
    // Chrome, Firefox
    result = /.*\s(.+)/.exec((new Date()).toLocaleDateString(navigator.language, { timeZoneName:'short' }))[1];
}catch(e){
    // IE, some loss in accuracy due to guessing at the abbreviation
    // Note: This regex adds a grouping around the open paren as a
    //       workaround for an IE regex parser bug
    result = (new Date()).toTimeString().match(new RegExp("[A-Z](?!.*[\(])","g")).join('');
}
console.log(result);

Result:

"CDT"