I over charged my iphone x for 5 hours does it harm my battery?

You can't overcharge an iPhone X.

Leaving it plugged in doesn't overcharge.

It can only help keep your battery at its best.

It absolutely, positively, will NOT hurt your battery. The phone can be plugged in 24 hours a day and it will not harm the battery.

Apple has never made a lithium battery powered device that could be over charged. International industry standards for SMART lithium battery technology requires over charge protection.