Comment by pjc50

    /*
    ** Test procedure for ParseRfc822Date
    */
    void TestParseRfc822Date(void){
      time_t t1, t2;
      for(t1=0; t1<0x7fffffff; t1 += 127){
        t2 = ParseRfc822Date(Rfc822Date(t1));
        assert( t1==t2 );
      }
    }

There's only two billion integers, guess we can test them all. Well, substantially fewer than two billion with that skip. I wonder if that completes in a few seconds.