There is well known issue with 'time' command described by teaCup here https://community.bistudio.com/wiki/time -

On overloaded servers (below ~ 10 server FPS), time readings are unreliable. Seconds actually take longer. While the clients keep a steady tempo, server time lags behind, resulting in considerable offset between client and server time (easily 30 minutes for a 2 hour game). Client time is synchronised to server time during JIP, but other than that it runs independently.

Since this issue is known for years (and assuming that it is not going to be fixed), it is BIS_fnc_loop's resposibility to workaround this by using something else to measure time.