The time on your device may have changed, possibly due to traveling abroad.
The solution differs depending on whether you are using the standard iCloud calendar or are synced with another account, such as Google Calendar.
For Google Calendar
The issue may be related to the settings on your Google Calendar.
Please review the time zone settings for your Google Calendar account.
For iCloud Calendar
If you're using iCloud Calendar, you can avoid this issue by fixing the time zone of the calendar.
Go to "Settings," tap on "Calendar," then tap "Time Zone Override." Turn on the "Time Zone Override" button and select the time zone you want to set.
By selecting your home location, the times won’t shift even when traveling abroad. However, please note that the time zone will not automatically change when you travel.
Unfortunately, we do not provide a feature to automatically fix shifted times. Please correct them manually as needed.