Blood Moons

Blood Moons are a in-game phenomenon that causes all enemies in the game to respawn after a certain amount of time. It has been speculated that more Blood Moons occur when you kill more in the game and there have been reports of them happening randomly by performing certain actions.

1. The Blood Moon Timer

As soon as you gain control in the Shrine of Resurrection, a timer starts counting up from zero at an interval of 1 unit every 4 in-game seconds. Since every 60 seconds is one hour in-game, this makes 360 units one in-game day.

This timer is only counting in-game, so when you enter a menu, change a rune or weapon, enter a cutscene, or activate dialogue, the timer stops counting until you resume. Another thing to take note of is when you're in "witch time" or "bullet time" the time is slowed down. At this time far there is no known location where this timer does not continue adding up.

Once the timer hits 2520, or 7 in-game days, a blood moon will activate the night after. There is a check when in-game clock passes midnight and if the timer is over 2520, it will reset to 0 and will make that day a Blood Moon day. That night, after the cutscene for the Blood Moon ends, the timer will reset again to 0 and the cycle will start again.

Data: https://docs.google.com/spreadsheets/d/11Pi6zi1R9qcsuWahJ-sUo5DRZ-oPjrY_Cw0T0URZeTU/edit

2. Manipulation.

So far no guaranteed means of manipulation has been found. What sparked this research was a post on the Breath of the Wild subreddit stating that the player present apples to the banana food offerings near the Yiga Clan Hideout and got a Blood Moon the next night. I and other various players have been able to reproduce this but I believe it's purely coincidence due to high timers on some players files. I have not been able to reproduce it consistently on low timers.