How late in the day can you drink a cup of coffee without it ruining your sleep?

I usually go to bed about 11:30PM and my last cup is around 9-10PM. I think I'm immune to it as it never keeps me awake.

I can also drink a cup right before bed and it relaxes me enough so I sleep.

Doesn't bother me.

I can drink coffee at any time and it doesn't affect my sleep.

4pm. I used to be able to drink it up until bed time, but after a heart scare a few years ago I was told to give it up. I just cut back.

It has no effect on my sleep.

Maybe 3-4pm . . . Any later then that it hopefully would be the weekend.

All intake stops before 8:00 P.M.

Dijestsion.