I recently had the same problem, was in all my towns. I thought about what I had done recently that maybe it could have effected my game, only thing I did was reinstall the sims4, so I uninstalled it went back to all my towns and the problem was fix everything was back to normal, no lagging, clock wasn't stuck, sims work fine. Just to make sure that was the problem I reinstalled the sims4 went back to all my towns and the problem was there again, clock was stuck but sims were moving, children missed school, parents didn't go to work etc....I uninstalled it again went back to everything and it was all back to normal again....For me the sims4 caused my problems I hope this might help someone it's very frustrating that there are so many bugs in this game.
I have a new computer up to specs more than enough to play this game so I new that wasn't the problem and I have cc downloaded never had a problem with that either but I did check all that out and it was fine ( it was just the sims4) not reinstalling it ever....