function days_between(date1, date2) {

    // The number of milliseconds in one day
    var ONE_DAY = 1000 * 60 * 60 * 24;

    // Convert both dates to milliseconds
    var date1_ms = date1.getTime();
    var date2_ms = date2.getTime();

    // Calculate the difference in milliseconds
    var difference_ms = Math.abs(date1_ms - date2_ms);
    
    // Convert back to days and return
    return Math.round(difference_ms/ONE_DAY);

}