Custom Time Cycle

Custom Time Cycle is a mod that allows changing the duration of Minecraft days and nights using a simple command, without changing tick speed.

License

This mod is licensed under GNU LGPLv3.

Usage

This mod is currently available for Fabric, Minecraft 1.21+1 and 1.20.5+6/1.20.4 (no longer updated). The Fabric API is required. When installed server-side, the mod is not required on clients.

Durations of days and nights can be configured across dimensions and are saved across server restarts / world saves.

This mod adds a simple command, /timecycle. Its usage is as follows:

• /timecycle status
  • Shows a simple status message displaying which time durations are currently in use in the current dimension.
• /timecycle set <dayduration> <nightduration>
  • Modifies the durations of the Minecraft day and night in the current dimension.
• /timecycle reset
  • Resets the durations of the Minecraft day and night in the current dimension.

Using the /timecycle command requires the timecycle.command permission or operator level 2.

How it works (technical explanation)

Each Minecraft dimension (also called a level within Minecraft's code) has 3 counters related to time:

• The game time counter:
  • Is incremented by 1 every server tick, and never resets.
  • Counts the amount of ticks that have passed in the dimension.
  • Can be read in-game by using the vanilla /time query gametime command.
• The day time counter:
  • Is incremented by 1 every server tick, and is set back to 0 when it reaches 24000.
  • Determines the time of day:
    • When at 0, the sun rises.
    • When at 6000, the sun is at its peak (noon).
    • When at 12000, the sun starts to set, and the moon starts to rise.
    • When at 18000, the moon is at its peak (midnight).
    • When at 24000, resets to 0, and the sun rises again.
  • This means a Minecraft day lasts 12000 day time ticks and a Minecraft night also lasts 12000 day time ticks.
  • In vanilla Minecraft, 20 server ticks occur every second, meaning one Minecraft day and night together last 20 minutes.
  • Can be read in-game by using the vanilla /time query daytime command.
• The day counter:
  • Is incremented by 1 every time the day time counter resets back to 0, never resets.
  • Counts the amount of days that have passed in the dimension.
  • Can be read in-game by using the vanilla /time query day command, or in the debug screen (F3) at the Local Difficulty line.

This mod simply changes the rate the day time counter increments at, and by how much it increments:

• For example, if you set the duration of the Minecraft day to 6000 day time ticks, the day time counter will be incremented twice as fast, so by 2 every server tick.
  • We can confirm this by running the /timecycle status command:

    Using day time tick rate (duration=6000)
    Incrementing 2 time ticks every 1 server ticks

• If you set the duration of the Minecraft day to 24000 day time ticks, the day time counter will be incremented at half the speed, so by 1 every 2 server ticks.
  • Once again, we can confirm this by running the /timecycle status command:

    Using day time rate (duration=24000)
    Incrementing 1 time ticks every 2 server ticks

If you want to read more about the way Minecraft time works, I recommend this page on the Minecraft wiki.