Y is my mail never on time and why does it get delivered after 5 or 6 o'clock. In the sawmill Rd area

It's can be caused by a number of factors, ie. where you are located on the route, the volume of mail that day, regular carrier or substitute, overburdened route, did your carrier have to help another carrier, etc. There us no guaranteed delivery time unless it is express mail.

I thought 9 to 5 lol

Because that is how big government organizations run.