0th Day Warping uses the state restoring effect of the 0th Day glitch to reload the previous entrance instead of a new area. If you die in that area before doing a 0th day warp, you can load the first entrance of it, regardless of the entrance you came from.
This trick is performed by activating Mayor's Warp by saving at the Hidden Owl Statue, then activating Song of Time Storage. Next, select "Yes" on the stored text box and load an area via one of the methods below. You will appear at the first entrance of the scene you activated 0th day in. This trick will only work on versions which allow saving at owl statues.
Activate 0th day while falling out of bounds above a void. If it is nighttime, there is no timing involved. If it is daytime, there is a tight window to activate it shortly before voiding.
This method only works on areas with Title Cards, which appear when you enter the area. Die into the loading zone and the title card will cause the Song of Time Storage text box to come up during the death cutscene. Activate 0th day before respawning.
This method works in areas without Title Cards.
Enter a loading zone 3 seconds after activating 0th Day. This is frame-perfect.