Semi...
Be careful about charging by the set or hour. The fact is some clients will hire you for a minimum time to get minimum rate when in fact that one little job can keep you from accepting any other.

The little day time jobs can be priced by the hour and you can do a couple of them in one day with the proper scheduling. Night time is a different animal. I charge by the night and they own me for 3-4 hours.

Eddie