Small Improvements and Bug Fixes

Thanks to @thebarefootboy for reporting a bug about the time announcement repeating at the end time. Along with fixing this, I modified the code so that it will say good morning at the user configured start time (instead of hardcoded 7 AM) and say good night at the user selected end time (instead of hardcoded 9 PM).

Thanks everyone. I plan to release my other home automation scripts as well. Hope they will be as helpful as this one to others in the community