Human Date Difference

utils.js

Date.daysBetween = function (date_now, date_future) {
    // get total seconds between the times
    var delta = Math.abs(date_future - date_now) / 1000;
    delta_orig = delta;

    // calculate (and subtract) whole days
    var days = Math.floor(delta / 86400);
    delta -= days * 86400;

    // calculate (and subtract) whole hours
    var hours = Math.floor(delta / 3600) % 24;
    delta -= hours * 3600;

    // calculate (and subtract) whole minutes
    var minutes = Math.floor(delta / 60) % 60;
    delta -= minutes * 60;

    // what's left is seconds
    var seconds = Math.floor(delta % 60);  // in theory the modulus is not required

    if (delta_orig < 60) {
        return seconds == 1 ? seconds + " Second" : seconds + " Seconds";
    }

    if (delta_orig < 60 * 60) {
        return minutes == 1 ? minutes + " minute" : minutes + " Minutes";
    }

    if (delta_orig < 24 * 60 * 60) {
        return hours == 1 ? hours + " Hour" : hours + " Hours";
    }

    return days == 1 ? days + " Day" : days + " Days";
}