How to ISO 8601 format a Date with Timezone Offset in JavaScript?

Question

Goal: Find the local time and UTC time offset then construct the URL in following format.

Example URL: /Actions/Sleep?dura

Answer 1

Here are the functions I used for this end:

function localToGMTStingTime(localTime = null) {
    var date = localTime ? new Date(localTime) : new Date();
    return new Date(date.getTime() + (date.getTimezoneOffset() * 60000)).toISOString();
};

function GMTToLocalStingTime(GMTTime = null) {
    var date = GMTTime ? new Date(GMTTime) : new Date();;
    return new Date(date.getTime() - (date.getTimezoneOffset() * 60000)).toISOString();
};