date difference js

dateDiff.js

// Reference - https://www.w3resource.com/javascript-exercises/javascript-date-exercise-8.php
var date_diff_inseconds = function (date1, date2) {
    let dt1 = new Date(date1);
    let dt2 = new Date(date2);
    return Math.floor((Date.UTC(dt2.getFullYear(), dt2.getMonth(), dt2.getDate(), dt2.getHours(), dt2.getMinutes(), dt2.getSeconds()) - Date.UTC(dt1.getFullYear(), dt1.getMonth(), dt1.getDate(), dt1.getHours(), dt1.getMinutes(), dt1.getSeconds())) / (1000));
};

var date_diff_inminutes = function (date1, date2) {
    let dt1 = new Date(date1);
    let dt2 = new Date(date2);
    return Math.floor((Date.UTC(dt2.getFullYear(), dt2.getMonth(), dt2.getDate(), dt2.getHours(), dt2.getMinutes()) - Date.UTC(dt1.getFullYear(), dt1.getMonth(), dt1.getDate(), dt1.getHours(), dt1.getMinutes())) / (1000 * 60));
};

var date_diff_inhours = function (date1, date2) {
    let dth1 = new Date(date1);
    let dth2 = new Date(date2);
    return Math.floor((Date.UTC(dth2.getFullYear(), dth2.getMonth(), dth2.getDate(), dth2.getHours()) - Date.UTC(dth1.getFullYear(), dth1.getMonth(), dth1.getDate(), dth1.getHours())) / (1000 * 60 * 60));
};

var date_diff_indays = function (date1, date2) {
    let dt1 = new Date(date1);
    let dt2 = new Date(date2);
    return Math.floor((Date.UTC(dt2.getFullYear(), dt2.getMonth(), dt2.getDate()) - Date.UTC(dt1.getFullYear(), dt1.getMonth(), dt1.getDate())) / (1000 * 60 * 60 * 24));
};

var getDateInLocalTime = function (date, timeZone) {
    var currentDate = new Date(new Date.setMilliseconds(0));
    var requiredTimeZoneDate = new Date(currentDate.toLocaleString("en-US", {
        timeZone: timeZone
    })).getTime(); // current time in specified time zone
    var currentTimeZoneDate = currentDate.getTime(); //My current time
    var timeZoneDifference = requiredTimeZoneDate - currentTimeZoneDate;
    var requiredDate = new Date(date);
    var requiredTime = requiredDate.getTime() - timeZoneDifference
    return requiredTime
}