I'm having the opposite issue...
I created a google token on May 25, 2016 and it should have expired Nov 25, 2016 essentially... But it is still active and pulling data. Is this a glitch?
Or are the tokens actually valid for longer than 6 months?
As far as I can see in my google dashboard there is no expiration date. It is fully authorized with your software just like any other app/connection.