When I was an hourly contractor, and was on call I would charge for calls I received outside of work (rounded to the nearest hour, so if the call took 5 minutes

When I was an hourly contractor, and was on call I would charge for calls I received outside of work (rounded to the nearest hour, so if the call took 5 minutes I would charge for the full hour) my boss approved all those hours. Of course answering an email that is not urgent is something I would wait until the next day to do. Also I will admit that if i was taking a call it was typically nothing mundane usually something was blowing up.