[KS+][Hard/Very Hard][Large][Adventure] Tree of Life

I reached the spot with the zapper, which made Juni remark that she should ask the chief about this. Yet he just asks me why I'm not going to the sky. Wasn't that exactly what I did to reach the zapper?

I've got all the powerups, Red, Yellow and Blue keys (not found Purple yet), all 49 temple collectables and 89 of the feathers. I've completed the main level and got to the credits. Two shifts at the top of the credits are blocked by the Purple Gate and 50GC achievement. Fine. I assume I unlock the 50GC mode by going to the right of the Temple collectable corridor and activating the 'night-mode' shift. But that shift just drops me back at the start of the credits. If I go to the top and use the return home shift, it takes me back to the start in 'day mode'

So, have I missed something or is the 'night-mode' shift broken?

EDIT: Never mind. I missed the "Sleep until night" feature. Easy to miss!

I reached the credits with all artifacts except for two of the final ones. Yet even though it looked like this should be locked behind all of them, I was able to access the night warp. I used it and was sent back to the beginning of the credits with no visible change. Then I went through the credits, yet it's still daytime. Was the night warp supposed to fail because I don't have all artifacts or is this some sort of bug?

Edit: I should note that after using the shift, I did revisit its location just to see if the sign changed (it didn't). But I didn't use it a second time.

Edit 2: I'm forced to conclude that I can't get the night shift to work. I got all artifacts now, yet it still does nothing. I'll have to put my playthrough on hold until someone can explain how it works.

Edit 3: Okay, I figured it out. So using the shift there doesn't actually switch between day and night like I assumed. It just unlocks the ability to use the bed to do that. I don't think this was explained very well. But I guess I can keep playing now. Still don't know if I was supposed to be able to access the shift without all artifacts, though.

Edit 4: Another glance at the editor made it clear that I was indeed not supposed to be able to access the shift without all the artifacts. I was missing two from the Sky Temple.