tlsdate is a much cleaner implementation of this idea, taking the time from the handshake. TLS 1.3 as it stands makes sending the server time optional.
The 'Date' header is tricky because it is a timestamp of when the document was generated, not when it was served. Caching proxies have no obligation to (and in most cases shouldn't) update the value.
The 'Date' header is tricky because it is a timestamp of when the document was generated, not when it was served. Caching proxies have no obligation to (and in most cases shouldn't) update the value.