Two expire headers in a response?

I am mapping a site, basically noting down all endpoints, headers in both requests and responses. In one response, I saw that the webs return these two lines in headers:

expires=Thu, 26-Mar-2020 09:34:36 GMT; Max-Age=2592000; path=/
Expires: Thu, 19 Nov 1981 08:52:00 GMT

What is the purpose of having these two headers, and why is the second expires time is in 1981? I have digged around but I have found no sources on this.