18 minutes

Certain major glitches in ALttP, if performed incorrectly, are described as freezing your game for "up to 18 minutes".

Some events in the game depend on timers or similar counters that count down once per frame until they reach a target value. When these events occur as intended, the counter will be initialized so that it takes an appropriately small number of frames.

When the events occur in a glitched state, they could start counting from an number that was being used for something else, causing a much longer delay than intended. There is a significant chance that the number starts lower than the target value, so you have to wait for up to 65,535 frames for it to wrap all the way around the sequence of 16-bit numbers.

At 60 frames per second, counting 65535 frames takes 18 minutes and 12.25 seconds.

Glitches that depend on counters like this will usually have some setup that initializes the counter to something reasonable, such as picking up a pot before performing Mirror Door.