Steps to reproduce
Experimenting in a slow (long-running) script.
Expected behavior
When you create a cache entry the created time-stamp to be reflecting the time of the call.
Actual behavior
L1 & L2 APIs have the created data available for a given cache item. The thing is that it's hard-coded against the global $_SERVER['REQUEST_TIME']. So for a script running for an hour, created will always be the start of that hour.
Frameworks tested
Which module / plugin were you using?