A Coutingdown timer

Question

Hey guys,
I have to make a countingdown timer with hours, minutes, seconds and miliseconds seoareted on the display. I would use HTML and JavaScript, but I'm having problems with it. Has semeone already made this?

Answer 1

https://code.sololearn.com/WkR8S16RxpzT/?ref=app

Answer 2

https://www.w3schools.com/howto/howto_js_countdown.asp

Answer 3

https://www.sololearn.com/Discuss/1678228/can-any-one-please-tell-me-how-to-create-3-hours-timer-in-html-page