I just wanted to add that because a lot of players were complaining about FPS rates and the litter in hunting grounds (like glooth bandits) they now announced it will be a daily occurrence every server save. However, some spawns are still needing to be fixed to have a reset as well. This news is dated September 16, 2019:
n order to combat littering in hunting grounds, we have introduced a new refresh mechanism.
Tomorrow's server save will result in a map refresh which affects all areas except cities and houses. Any items which are left on the ground will be removed. This will from then on be a daily occurrence. Cities where refresh mechanisms have existed previously will continue to function as before.
Good hunting,
Your Community Managers
https://www.tibia.com/news/?subtopic=newsarchive&id=5200
Before September 21st 2011 there were few different times of for the server saves. On this date Cip synchronised the daily server saves to improve maintenance processes. From then on, the daily server save takes place at 10:00 CEST/CET on all game worlds.
https://tibia.fandom.com/wiki/Server_Save