Dating site with no caches
For a discussion of the Cache-Control directives and how they are used, see Cache Control.
Expires entity-header Each time it serves a response, the server adds an explicit expiration time to the response entity by putting a value in the Expires entity-header field.
has precedence because explicit directives in the Cache-Control header always override implicit information like the Expires entity-header date/time.
If the max_age Cache-Control directive is present, then the freshness lifetime is calculated as follows: freshness_lifetime = The server specified expiration times in the Expires entity-header and the Cache-Control directives max_age or s_maxageare the main controls that the server has in the expiration mechanism of HTTP 1.1.
Calculating the age of a cache entry When calculating the age of a cache entry, it's important that a host should synchronize its clock to a globally accurate time standard by using NTP or a similar protocol.