If you try to pick a start date or deadline, and notice that the days of the week don’t align with the correct date, you are using an unsupported calendar format.
The date picker shows the wrong date
Things only supports the Gregorian calendar format. If you are using any other calendar format (Buddhist, Japanese, etc.), you will notice that the days of the week will not align with the correct dates when you try to pick a start date or a deadline.
You will need to switch to the Gregorian calendar format on your device to fix this.
- On your Mac, go to System Settings:
- On macOS 13 or later, go to System Settings → General → Language & Region.
- On macOS 12 or earlier, go to System Preferences → Language & Region.
If Things doesn’t immediately show the correct dates, quit and restart the app.
Reminders do not fire
If you are using a calendar format that isn’t Gregorian, you might also notice that the reminders you’ve set for your to-dos don’t fire. Please follow the instructions above to change to the Gregorian calendar format on your device to fix this problem.