iPhone 12 Calendar keeps on changing to back date [Fixed]

iPhone users are facing issue with the Calendar app that the Calendar keeps on skipping back to old date no matter how many times you change it to todays date. The iPhone calendar skips back to 2019 occasionally. The issue is intermittent but causing troubles to the iPhone users specially iPhone users with multiple Calendar are facing much issue due to iPhone Changing to old date in Calendar app. 

iPhone 12 Calendar skipping back to old date

The issue is seen across different version of iOS including iOS 14.5/14.6 on iPhone 12/11/XR/XS/8/7 , and while trying to isolate the Calendar to fix this issue, this also does not helps and iPhone calendar skips back to September 2019. For most of the user iPhone slips back to old date in the month of Sept 2019 which is the oldest date in Calendar.

For some user this issue can be seen while adding an event to the iPhone, the iPhone Calendar will  jumps back exactly one year. This seems to be bug in the iPhone Calendar as the iCalendar continually reverting to September 2019 date when endeavouring to enter Reminders, Events etc. And due to this issue iPhone users are missing important meeting and reminders. 

How to fix iPhone Calendar keeps on slipping to back date : iPhone 12 Pro max, 11,X,XR/iOS 14.6.1

Fix 1: Try restarting the iPhone

A normal glitch in the iPhone Calendar can be fixed by a normal reboot. Please try a normal restart and check if this fixes the issue.

Fix 2: Try deleting and reading calendars

If iPhone Calendar is changing to back date then you can try to delete the Calendar and re-add the calendar back to the iPhone and check if this helps.

Fix 3 : Toggle iCloud

As the iCalendar setting are synched with the iCloud , we recommend to Signout from iCloud Account (Go to Setting-> Tap on your profilephoto->Sign out) and reboot the iPhone. Once iPhone is ON, Sign in again to iCloud again.

Fix 4: Update the iPhone to latest version

The iPhone Calendar skipping back to older date is an iOS bug and present there from many older releases. A permanent fix for this issue will be provided by Apple in upcoming releases. You should keep your phone to latest iOS updates for a stable fix.

Source: Shudtech