Effects in Termina Field upon overwriting the Ocarina to a bottle:
- No music plays
- No monsters
- Missing NPCs (?)
- Some missing chests
- Some missing grottos
- It actually rains there on the 2nd day
- Ice on the Mountain Village entrance is gone
- Deku Flower near the observatory is missing
Other effects:
This happens if you have the Ocarina to a bottle, Ocarina on B, and the Hookshot overwritten by HSW (Hot Spring Water). Being stuck in the same day over and over again. This is what Groundhog Day really is.
Playing Oath to Order on the Clock Tower will warp you to outside of Clock Town on the west side (as shown in the linked video @ 6:25) acting as if you don't have a single boss remains. This is impossible to see in normal gameplay because the Oath to Order song is learned after getting one boss remains.
Game time is slightly but noticeably faster in the Deku Cycle (very first cycle in the beginning of the game), so this is one effect that doesn't carry over to bottle Ocarina. But Tatl telling you what to do (Navi mode) does.
I don't know any real use for this for anything other than keeping the same day (with Hookshot HSW) that does not make a negative impact to dungeons progress, but the speedrunner beat the game in one cycle after the Deku one and the 4th Day glitch is also infinite time. The game even becomes unbeatable with Ocarina bottle since access to the moon is denied.
Regardless, have anyone messed with Hookshot HSW for any interesting results? On the side of things to see completed sidequests back in time for any weird results.