This may help
https://www.nesmakers.com/index.php?threads/solved-4-5-9-countdown-timer-in-maze-module.6510/
But what i did was, a workaround.
Tiles are active when colliding with something here. So i made a variable.
When im colliding with tile "1" , i have the code DEC or INC a variable.
Then in code, have stuff happen when variable is at a certain position.
Also have it reset, say when it reaches #$00.
This may not be efficient. And if there is a vid tutorial on actual timers, i'm not sure.
But searching using the search tool on the forum may yield some
good results. Use a word like timer and only search titles.
There are already some timers set up, and i think people use those.
Although i don't have alot of knowledge on that subject, sorry.