Why is “Expires” 1981?

Question

My CRON Job returned an error that CRON job did not work. In that this was there:

Set-Cookie: PHPSESSID=2t2drultihqc         


        

Answer 1

It's an attempt to disable caching.

The date is the birthday of the developer Sascha Schumann who added the code.

From session.c:

Authors: Sascha Schumann  
         Andrei Zmievski  

// ...

CACHE_LIMITER_FUNC(private)
{
    ADD_HEADER("Expires: Thu, 19 Nov 1981 08:52:00 GMT");
    CACHE_LIMITER(private_no_expire)(TSRMLS_C);
}