How to Reset a Broken Calendar in The Sims 4 (MCCC + Fixes)
If holidays in your game start in the middle of the night, seasons change on random days of the week, and school exams have suddenly moved, these are all telltale signs that your calendar is broken. Let's break down why this happens and how to fix it.
The main culprit: changing the time speed in MC Command Center
In the vast majority of cases, calendar issues are caused by changing the in-game time speed through the MC Command Center (MCCC) mod. Its settings include a parameter that controls how fast time moves in the game. The default value is 25. The higher the number, the slower the in-game clock ticks.
It might sound tempting: more time for each in-game day. But there's a significant catch: the entire simulation slows down along with time. The MCCC developers explicitly warn that there's no way to slow down just the clock without affecting the game's entire underlying logic. What this means in practice is that your sim will still sleep for 6 hours and take a 15-minute shower – it'll just drag on two to three times longer in real time. Speeding sims up under these conditions isn't really an option either: they simply get bogged down in the slowed simulation. The actual payoff from a "stretched-out day" ends up being far more modest than you'd expect.
But that's not even the worst of it. At values of 32 and above, holidays and seasons start to malfunction: the game loses track of when scheduled events are supposed to occur. As a result, holidays kick off at one in the morning, festivals show up on the wrong day, and seasons stop changing on a fixed schedule. The calendar essentially goes off the rails.
If you've ever adjusted the time speed in MCCC, that's almost certainly the root cause of your problems. For long-term stability, it's best to stick with the default value of 25.
If MCCC isn't the issue
Sometimes players run into calendar shifts without ever touching the time speed settings. In that case, it's worth looking at other installed mods – particularly any that affect time, seasons, or holidays. Try temporarily removing all mods and checking whether the problem persists. If everything works fine without them, use the process of elimination to track down the culprit.
How to fix it: changing season and lifespan length
One of the most reliable ways to get your calendar back on track is to forcibly "shake up" the game's settings through a secondary save.
1. Open any save other than your main one (or create a new one).
2. Go to Game Options → Environment. Find the Season Length setting and change it to a different value (for example, switch from 14 days to 28).
3. Optionally, you can also change the sim lifespan: switch it to a different option (for example, from Long to Normal).
4. Save and return to the main menu without closing the game.
5. Load your main save, go back into the same settings, and restore your original values, the ones you had before.
6. Save, fully close The Sims 4, and relaunch it.
After that, holidays should fall back into place and start at the correct time.
Custom holidays can break the calendar too
There's another cause of issues that the community has flagged: user-created holidays added to the calendar manually. It seems that sometimes the event generation logic starts to glitch out. Events show up at odd times or don't trigger at all.
If the season and lifespan method didn't do the trick, try the following:
1. Delete all custom holidays from the calendar (make sure to save them first). Leave the default in-game events untouched.
2. Fast-forward time by roughly one in-game week.
During that time, new, correctly generated events should populate. Any holidays or festivals that were already sitting in the calendar in a "broken" state with the wrong times will simply pass – there's no need to wait for them to fix themselves. Starting with the next season, everything should fall back into place.
Once you've confirmed that the calendar has normalized, you can go ahead and re-add your custom holidays – they'll show up reliably at the times you set.
If nothing works
As a last resort, when none of the above methods have gotten the job done, the community recommends wiping the calendar clean of all events and rebuilding it from scratch. It's a lot of work, but it gives you the cleanest possible fresh start.
