Sleep Time Simulation
- By
Sleeping simulates the skipped night so loaded crops, machines, redstone, and animal ages can advance before morning.
Sleep Time Simulation
Let the world keep running while you sleep. Instead of jumping the clock straight to morning, Sleep Time Simulation processes the night while you stay in bed. Loaded crops and saplings get their normal chances to grow, redstone and furnaces keep ticking, and tick-based modded machines can continue working. Baby animals age through the night. Simulation starts without the usual bed wait and ends at morning once the required ticks have run.
A smooth Night progress bar above the hotbar shows how much of the night has been processed. The sleep darkness starts clear, peaks halfway through, and clears again by morning. The bar begins fading as you wake. You can turn the bar, darkness effect, and chat messages on or off independently.
Two simulation modes
- FULL_SERVER (default): Runs complete server ticks as quickly as the computer can process them while someone sleeps. This covers server-wide tick listeners as well as the loaded worlds. The player remains in bed until the simulation reaches morning.
- WORLD_BATCH: Runs extra world ticks in batches at the normal server loop pace. This can be easier to use on slower computers, but it does not advance every server-wide system. The progress bar and darkness are smoothed on the client so batch updates do not look stepped.
By default, mob movement and AI stay near normal real-time speed during either mode, while animal age and breeding cooldowns advance with the skipped ticks. Set normalMobTickRate = false if you want mobs to receive the extra movement and AI ticks too.
Compatibility and installation
- Minecraft: Java Edition 1.20.1
- Loader: Forge 47.x
- Install: Put the JAR in the
modsfolder. For multiplayer, install the same version on both client and server. - Other loaders: NeoForge has not been verified for this build
Only loaded chunks are simulated. Plant growth still follows ordinary light requirements and random chance, so one night does not guarantee a full crop or tree. Modded machines progress when their logic uses the ticks this mod advances; systems based on real elapsed time may behave differently. Large worlds and modpacks can make a sleep skip take longer in real time. Dedicated-server multiplayer has not yet been verified.
Configuration
Forge creates config/sleeptimesimulation-common.toml after the first launch. Close the game or server before editing it, then restart. The defaults work without any setup.
| Setting | Default | What it does |
|---|---|---|
simulationMode |
"FULL_SERVER" |
Choose complete accelerated server ticks or "WORLD_BATCH" extra world ticks. |
extraTicksPerTick |
64 |
Extra world ticks per normal server tick in batch mode. Range: 1–256. Ignored in full-server mode. |
maxSkipTicks |
24000 |
Maximum ticks simulated during one sleep. Range: 1–24000. A lower cap can stop the simulation before morning. |
normalMobTickRate |
true |
Keep mob movement and AI near normal speed while advancing age and breeding cooldowns. |
skipSleepDelay |
true |
Begin the skip immediately instead of waiting through the normal bed delay. |
showProgressBar |
true |
Show the Night percentage above the hotbar. |
useSleepDarknessEffect |
true |
Use the smooth 0% → 50% → 100% darkness curve. false restores vanilla sleep darkness. |
showChatMessages |
true |
Show sleep-skip start and finish messages. |
sleepOverlayMaxOpacity |
170 |
Darkness at the 50% midpoint. Range: 0–255; higher is darker. |
progressSmoothingMillis |
120 |
How quickly the bar and darkness catch up to new progress updates. Range: 16–1000 ms. |
progressBarFadeMillis |
500 |
Time for the bar to fade once the skip completes. Range: 100–5000 ms. |
Example: For the gentler batch mode with no chat messages, set simulationMode = "WORLD_BATCH" and showChatMessages = false, then restart Minecraft.
The Sleep Time Simulation Team
