I recently needed a list of all of the countries I had been to and the dates I was in each. Naturally I thought of my Google Timeline (formerly "location history") as a way to do it. Google Timeline is a data store of all the places you have been over time. It is extremely detailed and, at least for me, seems relatively complete. To view yours, go to your timeline.
To get your timeline in a form you can manipulate, you can use Google Takeout, Google's data portability service (big kudos to Fitz and the whole Google Takeout team). My file contained over 2.8 million locations, so the first thing I did was used geopy to throw out any locations that weren't at least 50 miles apart (see code). That left ~12,000 entries. For each of the 12,000 entries, I rounded them down to reduce calls, then used geopy to reverse geocode (look up the street address based on the latitude and longitude), threw out everything but the country, and outputted any change with a date (see code).
This was somewhat similar to a project I did more than six years ago, though Google had changed the format of its timeline file, so I needed to rewrite it. It should be pretty easy to also produce a country chart, but I haven't done that yet.
I continue to believe that data portability will not take off and be demanded by users until there exists useful things to do with the data. Hopefully scripts like these can help contribute to that.