I have this problem too. I think it has to do with it not handling split times properly (multiple opening hours per day).
In my case a place is open today from midnight till 3am and then from 10am until midnight. But it says it is currently closed. The time on my computer is 12:37pm, and my VPN is connected to Sweden (same time), so it's not that it is using my IP to find the wrong time. So I think it just doesn't handle split times properly. I would assume it works based off local time anyway, for obvious reasons.