For some reason most of us are too afraid of just going home at 5:00 much less asking for reduced hours.

My whole working life, I've never used an alarm clock, and I never stayed late unless I was late on a commitment that I made. (This is not the same as some artificial deadline dreamed up by someone else.)

I come in late, go home early, sometimes I don't even show up—whatever.

If you do this consistently, and deliver in your role of course, people will get used to it and they'll stop bothering you about it.