What are the time limits on token and refresh tokens?

Access Token, refresh Token and access code expire in 7200 seconds. You get only one refresh token for an accessToken. You can get a new pair of access and refresh token anytime before 2 hour expiration period. Here is the link for that.

There is a feature called "QuickConnect" where users login once and we refresh their data on our side periodically unless you/your user unsubscribe from it. Here is the link for more information.