the method to synchronize Google Calendar with Microsoft Outlook

Export the Google Calendar data to a .ics file, open it with Microsoft Outlook by click on the file, not import the data into Outlook. Then, in Outlook there will be a new calendar content all the data in the .ics file.

In Outlook, export the new calendar out as a .csv file, open it with Microsoft Excel, sort the data by "modification date and time", then keep the newly modified data, delete all the older ones. Save the .csv file.

In Outlook, import the .csv file, then, the newly modified data exist in the Outlook data file, the .pst file.

To update the newly modified data in Outlook to Google Calendar, just do the same thing, just do it backwards. When the .csv file ready, then import it into Google Calendar.

Most important thing!!!! Before do all the procedure above, make a copy of the Outlook data file, the .pst file.