How to make a timer

[ashen cosmos]

Like when you leave a certain part the timer will start and stop when they go touch another part. The time will also be displayed on a gui

[limber pilot]

where code

[solemn abyss]

os.time (end) - os.time (start)

Which will show it in full seconds, if you need it smaller then you’ll have to do some magic with math and logic