Age Header
A response header added by caches indicating how long (in seconds) the response has been stored. The remaining freshness is calculated as: max-age - Age. When Age equals or exceeds max-age, the content is stale.
A response header added by caches indicating how long (in seconds) the response has been stored. The remaining freshness is calculated as: max-age - Age. When Age equals or exceeds max-age, the content is stale.