Google Calendar: Undoing Import

Google Calendar allows calendar items to be imported from a CSV. However there may be times where reversing the import is required — for example, if there a timezone problem in the CSV file. There is no reverse function as such but the import can be undone as follows:

1. Go to Settings (cog) → Settings.

2. Click Import and Export.

3. Click Export.

   The export will download a .ZIP file which will contain .ICS files for each calendar.

4. Extract the .ZIP file and open the required .ICS file with a text editor.

   Check the LAST-MODIFIED fields. All the imported items will have almost exactly the same import time.

   Additionally, the items are ordered by creation, so the imported items are at the end of the file.

5. Remove those items.

   Each item begins with BEGIN:VEVENT and ends with END:VEVENT.

   Be sure to keep the last line in the file: END:VCALENDAR

6. Create a new calendar by clicking + next to Other Calendars.

7. Import the file into the new calendar.

8. When you're sure the information is correct, delete the other calendar.