There is currently no option to have cache valid for limited time.
epoch is pretty much useless, invalidating cache every second.
It would be nice to have additional templates for “timestamp today at 00:00” and “timestamp 1st of this month at 00:00”
Better yet would be an option to specify cache TTL on
save_cache step. That would solve stale cache problem nicely while keeping immutability concept. May be s3 object expiration can be utilized for that.