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

function setDate(){
    var now = new Date();
    now.setMinutes(now.getMinutes() - now.getTimezoneOffset());
    var timeToSet = now.toISOString().slice(0,16);

    /*
        If you have an element called "eventDate" like the following:

        

        and you would like to  set the current and minimum time then use the following:
    */

    var elem = document.getElementById("eventDate");
    elem.value = timeToSet;
    elem.min = timeToSet;
}