The HTTP Expires response header indicates a specific date and time, after which the HTTP response is considered expired.
The Expires header is used to inform the client as to when the current HTTP response expires. It contains a specific time and date, although if it instead contains a zero
0 then the HTTP response is already expired.
Expires: Wed, 01 Jun 2022 08:00:00 GMT
The Expires header is used to inform the client when, specifically, the HTTP response expires.