javascript time zones code example

Example 1: javascript set date to timezone

var d = new Date("2020-04-13T00:00:00.000+08:00"); /* midnight in China on April 13th */
d.toLocaleString('en-US', { timeZone: 'America/New_York' });
//=> "4/12/2020, 12:00:00 PM"
// (midnight in China on April 13th is noon in New York on April 12th)

Example 2: get user time using timezone javascript

function calcTime(city, offset) {
    // create Date object for current location
    var d = new Date();

    // convert to msec
    // subtract local time zone offset
    // get UTC time in msec
    var utc = d.getTime() + (d.getTimezoneOffset() * 60000);

    // create new Date object for different city
    // using supplied offset
    var nd = new Date(utc + (3600000*offset));

    // return time as a string
    return "The local time for city"+ city +" is "+ nd.toLocaleString();
}

alert(calcTime('Bombay', '+5.5'));