By Ryan Bushey at Business Insider:
Google announced this week on that it added a new feature on the Google Takeout service.
Now, users have the ability to export data from their various Google accounts, including Gmail and Google Calendar, in order to create a customized archive or carry over all your info to another service. The Gmail portion of the service will roll out over the coming weeks, but it is available for other Google apps.
This is how you can create your own personal database from your Google accounts.
Head to Google Takeout, log in with your Google credentials, and click the blue "Create an archive" button.
The next screen will give you options on what to archive. As of right now, you can choose from 11 products. Lets' start with Google Calendar. Click archive.
The process moves quickly. You should receive an email notification too. Download your archive. It expires within a few days, so do it quickly.
Once you download the zip file, calendar information should appear in whatever calendar program is on your computer. You can also save information from Google Hangouts chats and other services. Soon, you'll be able to download all your data from Gmail
Via Business Insider.