Date difference in Javascript (ignoring time of day)

Question

I\'m writing an equipment rental application where clients are charged a fee for renting equipment based on the duration (in days) of the rental. So, basically, (daily fee *

Answer 1

If you want whole days for your student camera rental example ...

function daysBetween(first, second) {

    // Copy date parts of the timestamps, discarding the time parts.
    var one = new Date(first.getFullYear(), first.getMonth(), first.getDate());
    var two = new Date(second.getFullYear(), second.getMonth(), second.getDate());

    // Do the math.
    var millisecondsPerDay = 1000 * 60 * 60 * 24;
    var millisBetween = two.getTime() - one.getTime();
    var days = millisBetween / millisecondsPerDay;

    // Round down.
    return Math.floor(days);
}