Why don’t I get hungover when day drinking?

I work nights and generally keep a night shift schedule on my days off. If I want to go out drinking I just get up at like 5, head over to a bar at like 8, and drink until I’m drunk, leave at like 1 and head home. I almost always stay up until the effects of the alcohol wear off, and other than an upset stomach I never get hungover like I would if I had gone to sleep right after getting home. Why is this?