When I use Game Time Speed, holidays in Seasons happen on the wrong days/months. How do I fix this?
When Game Time Speed is changed, all of the running internal alarms that EA creates for daily events are automatically reset to be at the correct time/day (like career start/end). However, holidays are already scheduled and in the save file so they are not adjusted like the other alarms. This will make them show-up at the wrong time on the calendar. The holidays can be deleted from the calendar and then set-back to the right day and time and they will be correct going forward, until Game Time Speed is changed again.
from the MCCC website <>
You could try changing this setting in MCCC, then starting a new save to see if it works, but changing game time speed in MCCC will interfere with other in game actions and is not recommended.>