Write a Python function that gets the current period number and returns it as an integer. Valid period numbers are 1 through 7 inclusive. If the time is not during the school day, then return 0. If it is during passing time, return -1. If it is during common lunch, return -2. If it is homeroom or common tutorial, return -3. The minute a period ends should count as passing time. NOTE: The hour will be in military time, so an hour of 13 means 1 PM, for example.