If your calendar events are not syncing correctly, or if you see duplicated entries and missing dates, resetting your Android calendar memory can fix the problem. Here is how to safely clear and rebuild your calendar storage.

1

Important Warning & Backup

Before you follow this guide, you must understand how Android saves calendar data:

Risk of Data Loss: Clearing the system calendar memory will delete all calendar data currently saved on your phone. Any events synchronized with cloud services (like Google Calendar, Microsoft Exchange, or Outlook) are completely safe and will download again. However, local offline calendars (calendars not linked to a cloud account) will be permanently lost. Please make a manual backup of your local calendars before moving forward!

2

How to Reset the Storage App

Because calendar data is managed by Android itself (not by aCalendar), you need to reset the system storage app:

1

Find System Apps

Open your phone's main Settings app and go to Apps (or Apps & Notifications). Tap the three dots in the top corner or look for the filter option to select Show system apps.

2

Clear Calendar Storage Data

Scroll through the list and open the app named Calendar Storage (do not confuse this with the standard Google Calendar or aCalendar apps). Tap on Storage, and then select Clear Data (or Clear Storage).

3

Rebuilding Your Calendars

After clearing the storage, your calendar app will appear empty. Follow these steps to restore your entries:

Trigger a Fresh Cloud Sync

Go back to your phone's main Settings → Passwords & Accounts (or Accounts). Select your cloud account (like Google), tap Account Sync, turn the Calendar toggle switch off, and turn it back on. This forces Android to download a clean copy of your schedule from the server.

Wait for the Synchronization

It can take several minutes for Android to download all your past and future appointments. Keep your internet connection active. Once the system finishes synchronizing, open aCalendar, and all your cleaned-up events will show up correctly.