Each day in Legends: Arceus lasts 24 minutes, and each real-time minute is one in-game hour.
In-game time is saved; if you save and reboot your game, it will start at the same time. The save block for in-game time is 203A7F34 and stores a double value equal to the number of minutes. The function that converts this to the hour is at sub_71024AB9F0 in version 1.1.1.
There are 4 different times of day, which I will call Dawn, Day, Dusk, and Night. I do not believe that there are official names, but you may see other names such as Dawn = Morning, Day = Midday, Dusk = Evening on various fansites.
Times will be written as 24-hour time. You can subtract 12 to get the 12-hour time if you prefer.
I recorded a video of the full day cycle, which also shows when Night starts and ends [video]. The hour is displayed on the top right. You may notice the hour actually ticks to 24 very briefly, and the game immediately corrects it to 0 [video].
When sleeping to a specific time of day, picking each of these options will set the time to the start of a specific hour.
| Selection | Hour |
|---|---|
| Until morning | 7:00 |
| Until midday | 12:00 |
| Until evening | 19:00 |
| Until nightfall | 21:00 |
I could not find any functional differences in spawners between Dawn and Day. Every spawner for these two times appears to have identical tables. It may be better to sleep to Morning instead of Noon if you are looking for daytime Pokémon since you will have more time.
| Time of Day | Hours | Minutes |
|---|---|---|
| Dawn | 5:00 - 11:59 | 7 |
| Day | 12:00 - 18:59 | 7 |
| Dusk | 19:00 - 20:59 | 2 |
| Night | 21:00 - 4:59 | 8 |
Since there is no difference between Dawn and Day normally, I verified this by modifying a spawner to generate Arceus once Dawn ended [video].
Some Pokédex entries such as Yanma and Budew require them to be caught at a specific time of day. It's worth noting that any Pokémon that must be caught during "daylight" is eligible during both the Dawn and Day times. Sleeping to Morning will give you more time to work on these tasks.
| Dex Time Required | Hours | Minutes |
|---|---|---|
| Daylight | 5:00 - 18:59 | 14 |
| Evening | 19:00 - 20:59 | 2 |
| Night | 21:00 - 4:59 | 8 |
Examples:
- Budew requires a daylight capture and works at 5:00 [video].
- Yanma requires an evening capture and works at 19:00 [video].
The moon in Legends: Arceus has 8 phases just like our real-life moon. Each phase lasts 2 in-game days.
The moon phase is stored in save block 9E4635BB as a number that ranges from 0-15, where 0-1 = New Moon.
| Phase | Image | Phase | Image | |
|---|---|---|---|---|
| New |  |
Full |  |
|
| Waxing Crescent |  |
Waning Gibbous |  |
|
| First Quarter |  |
Last Quarter |  |
|
| Waxxing Gibbous |  |
Waning Crescent |  |
These images from Legends: Arceus were taken at exactly 23:00 on a clear night in the Alabaster Icelands.
The new moon is simulated as a dark area of sky with no stars!
The phases are in order down the first set of column, then down the second set of column.
The moon phase naturally advances at the end of Night, which is at 5:00. Even though the moon phase can be advanced to the Full phase at 5:00, Ursaring can only evolve if the time is between 21:00 and 4:59.
From what I can tell, sleeping advances the moon phase if sleeping until the new time would pass 5:00. For example, sleeping from Night (21:00) to Morning (7:00) would cause the moon phase to advance by 1, but sleeping from Midday (12:00) to Evening (21:00) would not.
Sleeping to the same time repeatedly advances the moon phase as well. This may seem strange, but remember that time is tracked more specifically than the hour. If you sleep from 21:01 to 21:00, this would effectively be sleeping through all night and most of the next day.
Since evolving Ursaring requires the time to be between 21:00 and 4:59, sleeping to nightfall repeatedly is the fastest method to reach the Full Moon requirement. The evolution will show "Compatible" if you hover over a Peat Block between these times. To make this check faster, you can put the Peat Block in the first space in your inventory. The moon will not start rising in the sky until about 22:00, but it does not need to be visible for the evolution to be possible.
