Internet Explorer Daylight savings - detect using Javascript

daylight-ie.js

function stdTimezoneOffset() {
    var d = new Date();
    var jan = new Date(d.getFullYear(), 0, 1);
    var jul = new Date(d.getFullYear(), 6, 1);
    return Math.max(jan.getTimezoneOffset(), jul.getTimezoneOffset());
}

/**
 * Gets offset of current timezone and calculates if it has daylight timings enabled.
 * @returns {boolean}
 */
function dst() {
    var d = new Date();
    return d.getTimezoneOffset() < stdTimezoneOffset();
}