This is a direct E-mail from the creator of the game, I couldn't find any reliable information on it online so I asked directly. Here is the response:
The times when a character appears are set by the game and always the same, but which one of them appears is random - so it will also be matter of luck which ending you'll get.
The people start going to the well at "midnight" (when the in-game clock is set to XXX:00:00:00) and continue to do so for about 13 hours.
Here are the hours after "midnight", a character appears:
- 0
- 0.849
- 1.483
- 2.166
- 2.716
- 3.365
- 4.849
- 5.482
- 6.165
- 7
- 8.214
- 9.482
- 10.516
- 11
- 12.216
- 12.849
In in-game time:
XXX:00:00:00
XXX:23:09:03
XXX:22:31:01
XXX:21:50:02
XXX:21:17:02
XXX:20:38:06
XXX:19:09:03
XXX:18:31:04
XXX:17:50:06
XXX:17:00:00
XXX:15:47:09
XXX:14:31:04
XXX:13:29:02
XXX:13:00:00
XXX:11:47:02
XXX:11:09:03
It will then take 777,6 seconds for the character to reach the well and operate the bucket. Good luck!
-Anselm
[Adding to it, it takes roughly 42 minutes (including 10 minutes of waiting before the dialogue) to get from shades room to the top of the blocked off tunnel (rough estimates on my runs and WR) so you have to plan accordingly for either of the endings.
Edit: You don't need to look at the person appearing, just fully trust the numbers from the creator, the person operating the bucket takes around 1:33 min to operate the bucket so here are the times where you have to be at the bucket:
XXX:00:00:00 → XXX:23:58:27
XXX:23:09:03 → XXX:23:07:30
XXX:22:31:01 → XXX:22:29:28
XXX:21:50:02 → XXX:21:48:29
XXX:21:17:02 → XXX:21:15:29
XXX:20:38:06 → XXX:20:36:33
XXX:19:09:03 → XXX:19:07:30
XXX:18:31:04 → XXX:18:29:31
XXX:17:50:06 → XXX:17:48:33
XXX:17:00:00 → XXX:16:58:27
XXX:15:47:09 → XXX:15:45:36
XXX:14:31:04 → XXX:14:29:31
XXX:13:29:02 → XXX:13:27:29
XXX:13:00:00 → XXX:12:58:27
XXX:11:47:02 → XXX:11:45:29
XXX:11:09:03 → XXX:11:07:30
Meaning that to arrive there (around) on point you'd have to start walking, from your room at around:
XXX:23:58:27 → XXX:00:40:27
XXX:23:07:30 → XXX:23:49:30
XXX:22:29:28 → XXX:23:11:28
XXX:21:48:29 → XXX:22:30:29
XXX:21:15:29 → XXX:21:57:29
XXX:20:36:33 → XXX:21:18:33
XXX:19:07:30 → XXX:19:49:30
XXX:18:29:31 → XXX:19:11:31
XXX:17:48:33 → XXX:18:30:33
XXX:16:58:27 → XXX:17:40:27
XXX:15:45:36 → XXX:16:27:36
XXX:14:29:31 → XXX:15:11:31
XXX:13:27:29 → XXX:14:09:29
XXX:12:58:27 → XXX:13:40:27
XXX:11:45:29 → XXX:12:27:29
XXX:11:07:30 → XXX:11:49:30
Please don't take my word on it, my numbers are very rough taken mostly from my own runs, and for the sake of my sanity the subtraction and presentation was done by AI]
