How best to implement a timer without using a forge component

I would like to click on a button and display a timer and also click another button and stop the timer. When i stop the timer i then save the start time and end time in the database. What can i use for the timer? which is not a forge component

If you want to build something by your own try something like this : https://www.w3schools.com/howto/howto_js_countdown.asp  


Just curious, any specific reason to not use the already available forge components ?