time - How to calculate ms since midnight in Javascript

Question

What is the best way to calculate the time passed since (last) midnight in ms?

Answer 1

Create a new date using the current day/month/year, and get the difference.

var now = new Date(),
    then = new Date(
        now.getFullYear(),
        now.getMonth(),
        now.getDate(),
        0,0,0),
    diff = now.getTime() - then.getTime(); // difference in milliseconds