I'm a beast from approximately 3pm to 5pm. I might get about an hour's worth of real work done during the rest of the day. They need a warm body during standard

I'm a beast from approximately 3pm to 5pm. I might get about an hour's worth of real work done during the rest of the day. They need a warm body during standard business hours, but honestly if I worked from 2pm to 7pm I'd probably be twice as productive as I currently am working 8am to 5pm, but alas saying "70% of of the time I'm not doing anything useful" isn't a great way to convince the higher ups that they should hire an additional person to do the busy work.