I found that this was not documented in the API Reference, and not in the Get Activity Summary section of the API Docs, but it was present in the prior section in the API Docs: "Contact Activity Reporting Overview". It clarifies that the limit is 5 years. ... View more

It appears through trial and error testing that the start and end keys will yield an error if they are more than 5 years and 2 days apart. I have to guess that there is some code internal to the API processing that is expecting the range is no larger than a certain number of days apart (roughly equivalent to  5 years) but the slight extra offset maybe because of leap year and/or including starting and ending date or something like that. Can someone confirm there is a 5 year limit to the range? I am just trying to verify it really is time length based and not on the number of campaigns returned. ... View more

If the access token is expired, will it return 401 The Access Token used is invalid, and after detecting that has happened, that is when to use the Refresh token to ask for another Access Token? Or is it recommended to periodically request a new access token to keep the Access Token from expiring? ... View more