Maximum expiration time for Cache Services in Google Apps Script
===

Does anybody know what is the maximum expiration time for Cache Services in Google Apps Script? I am running my script on Google Sites and have tried to run a trigger that re-caches the cache, but the cache seems to still expire overnight and I am not certain how long it lasts. If anyone has timed the actual length of the cache it would be good to know - unfortunately, Google hasn't made this info public. 