Any good tutorials for timer values

So this is probably been asked a lot. I have been working with a lot of functionality with timers lately and I always been forgetting the values for converting seconds for a countdown clock or related time functions. Soi has to look up for it multiple times. I know there are libraries for this but anyone has a good tutorial for any time-related function or a cheat sheet for conversion. ?

Use MomentJS.

Its doc can serve as a cheatsheet. It also has guides section.

https://momentjs.com/guides/