Need help setting business hours?

Ok I have an electronics repair store. Cell phones,computer,gaming systems etc.. and I'm trying to figure out what hours would be best for me and the customers? I was think Mon-sat 9am to 7pm and sun 1pm to 5pm? What do you think? As a side note my compitetion is open from 10-6pm mon-sat and closed on sun. So any opinions are welcome and thanks in advance!