Consider going to bed early enough that you wake up without an alarm clock. It's not going to 100% prevent you from ever falling asleep during the day, but it'l

Consider going to bed early enough that you wake up without an alarm clock. It's not going to 100% prevent you from ever falling asleep during the day, but it'll sure help. Personally, my intellectual capabilities are at their peak in the first few hours after I wake up.