This is an issue I've noticed in many of my save files, and many people might have experienced this bug, too.
The day counter can go off when moving from the Volcano to the SW world. A few examples I've experienced are these:
1. Entered Volcano on day 121, exited on day 124. The game crashed and closed, upon reloading the save it said I'm still on day 121. The game luckily reloaded the save (I lost a save file to a similar issue before) and sent me back on day 121 with all my loot from the Volcano. No damage occured but it was still annoying.
2. Entered Volcano on day 130, upon loading the Volcano the day counter said I'm on (about) day 1200 on world 1 (my world was Shipwrecked 6-1200). Again, no damage occured to the file but it was a very obvious, annoying bug.
The game seems to crash often when moving between Shipwrecked and the Volcano and all these day counter problems follow the crashes.
I'm very scared of going to the Volcano again as I'm scared the bugs could get worse like the gamebreaking glitch I mentioned before. I really hope it could be fixed. Thank you!
1. Enter the Volcano 2. Exit the Volcano, game might crash 3. Results in unsynchronized day counter