Hi Adorama,
Welcome to OSM, and thanks for your valuable contributions. 

OSM has a standard for recording opening hours and service times, which you can find here: https://wiki.openstreetmap.org/wiki/Key:opening_hours. You used it correctly for the police station, but not for the others.

It's also not right to add building=* tag to an amenity if you are mapping the entire land area it covers. The building tag is for buildings only.

Happy mapping!

Best,
Sam