Has anyone ever created a timer using JavaScript?

I am creating an HTML page that has a button that when clicked, starts a timer starting at 00:00:00 and counts upward (hh:mm:ss). This is not for a homework… I’m learning this on my own. I looked at the examples in w3schools and the JavaScript examples there either display the system time or start counting 1,2,3,4… seconds. I have not been able to find an example anywhere a counter starts at 00:00:00 begins counting upward by seconds and uses the hh:mm:ss format. I’m open to using VBscript or something else. Thank you.