Time
This article documents how time works in Breath of the Wild.
Summary
About time
Time starts at 05:15 and will flow normally until 11:00 is reached. Activating the Great Plateau Tower sets the time to 11:00, shows the time on the UI and restores the normal flow of time.
However:
- If the Shrine of Resurrection exit cutscene has not been played, the time of day is set to 05:15 and frozen.
- If that cutscene has been played, but Link does not have the Isolated Plateau quest, time cannot go past 11:00.
About scheduled blood moons
Blood Moons occur at midnight if and only if the WM_BloodyDay flag is set. There is no way to force blood moons to be scheduled via gameplay actions.
That flag is set the night before at midnight if Link has left the Plateau and if the Blood Moon timer has reached 7 in-game days. Not 7 days and 15 minutes, but exactly 7 days (2520/360 = 7). Also, note that Link does not need to pass time at a campfire after the WM_BloodyDay flag is set.
The Blood Moon timer starts ticking as soon as Link has left the Shrine of Resurrection normally. Any time spent in a state where even the main game timer is paused does not count. However, you do not necessarily need to be in the open world: time spent in shrines, divine beasts, etc. does count.
Passing time at a campfire or sleeping repeatedly does not help trigger a Blood Moon at all. Quite the opposite, as the timer does not advance during cutscenes.
Details
Internally, time of day is stored as a float in the [0.0, 360.0] range. 0.0 is 00:00 and 359.x is 23:59.
When the game starts, time is set to 78.75 (05:15) and the Bloody Moon end reserve timer is set to 0. If you have an existing save file, the game timer is reloaded from your save.
Every game tick
If the Shrine of Resurrection exit cutscene (Demo103_0) hasn't played, time is reset to 78.75. This means that if you manage to clip out of the Shrine of Resurrection and skip that cutscene, the game clock will be stuck at 05:15.
Otherwise, if there is no active event/cutscene:
- The game timer is incremented by 0.0083333 × elapsed frames. Effectively, this means that 1 in-game minute = 1 real-life second.
- If Link hasn't received the The Isolated Plateau quest and if the current time is >= 165.0 (11:00), the time is forcefully set to 11:00. Effectively, this means that time will not get past 11:00 until the Great Plateau Tower is activated and the Old Man cutscene is triggered.
- If the timer reaches 360.0 (midnight), the game performs special checks. See the next section.
- A value called the blood moon timer is also incremented by 0.0083333 × elapsed frames.
Afterwards, if the "Bloody Moon end reserve timer" is non zero, it is decremented. If the new value is zero, the WM_BloodyDay flag is cleared.
Every time the timer reaches 360.0 (midnight)
First, WM_NumberOfDays is incremented. This has an effect on the moon cycle.
If a Blood Moon is scheduled:
If Blood Moons are "prohibited" (see below for a full list of conditions), the timer is set to 2880.0 and nothing happens. Otherwise, the Blood Moon cutscene (Demo011_0) is triggered and the timer is reset to 0.0.
The game then determines whether to schedule a Blood Moon or not:
If the player has left the Great Plateau and if the Blood Moon timer is > 2520.0 (7 in-game days):
- The WM_BloodyDay flag is set to true, which means that a Blood Moon is scheduled for the next night.
- The Blood Moon timer is reset to 0.0.
Otherwise, the "Bloody end reserve timer" is set to 150. This ensures that WM_BloodyDay is cleared 5 in-game minutes (= 5 seconds in real life) after a Blood Moon occurs.
Blood Moon inhibitors
If any of the following conditions are true, the Blood Moon cutscene will not be triggered.
- Link is not in the main overworld (e.g. in a shrine or Divine Beast)
- Link is in Hyrule Castle (i.e. the Hyrule Castle 3D minimap is visible)
- The BloodyMoonProhibition flag is set: Blood moons are prohibited by an event (cutscene, minigame, etc.).
- This flag is called by the DisableSaveAndWarp function, which used by all minigames, the section of "The Stolen Heirloom" where the Yiga Blademaster is fought, and the Dark Beast Ganon battle.
- The only time the BloodyMoonProhibition flag is set by itself is during the One-Hit Obliterator challenge in the Champions' Ballad, so that saving and warping are allowed.
- Vah Medoh battle
- Vah Naboris battle
- Vah Ruta battle
- Link is fighting Dark Beast Ganon (for good measure, since BloodyMoonProhibition is already set)
- Some condition involving the Sky Manager
However, these conditions do not prevent the Blood Moon timer from advancing, or the WM_BloodyDay flag from being set.
Note: The Vah Rudania battle is missing from the list. Blood Moons actually can occur during this segment, and will revive the Moblins but not the Sentries (as Sentries have the RevivalNone flag). This is because the event does not call DisableSaveAndWarp, and instead independently sets the WarpProhibition and KillTimeProhibition flags, in order to allow saving. Whether the developers intentionally allowed Blood Moons to happen during this segment, or simply forgot to set the BloodyMoonProhibition flag, is unknown.
Special case: passing time at a campfire or sleeping
When you pass time at a campfire or sleep, the time is instantly set to the destination time. The game never speeds up or slows down the flow of time.
If the time change causes the clock to cross midnight, the game sets a special flag that causes the Time Manager to run the "handle new day" function once, even if it's not midnight. The game also explicitly checks[1] if a Blood Moon was scheduled to happen and triggers the cutscene if needed.
Moon type
The moon type is calculated based on the number of in-game days (WM_NumberOfDays). The exact formula is (numberOfDays + x + 1) % 8[2], where x is equal to 1 if the current time is > 180.0 (noon) and % is the modulo operator.
If a moon type was set manually (for instance using AIDef:Action/EventSetMoonType), that value will be used as the moon type. It is unclear whether the game ever sets the moon type manually.
The moon schedule has nothing to do with the blood moon schedule.
Moon phases
Here are the possible values and associated phases:
- 0: Full Moon or Blood Moon or on a Bloody Day after 04:00
- 1: Waning gibbous
- 2: Third quarter
- 3: "26th-day"
- 4: New moon
- 5: Waxing crescent
- 6: "Seven-day"
- 7: "13-day"
References
- For more technical details, read the article on the WorldMgr. Sections of that article were extracted from it and simplified here.