Just in case you've forgotten the details, kindly permit us us to jog your memory, and help you recall that back in Amazing Spider-Man (Vol. 2) #12, the creative team of Macchio/Mackie/Byrne decided that maybe there were too many symbiotes. Thus they had Venom re-absorb from Carnage the symbiotic spawn that he had unwittingly gifted him so long ago, leaving human host Cletus Kasady with no trace of him former super-powers.
Kasady made one appearance without his symbiote, in Peter Parker: Spider-Man (Vol. 2) #13, but for whatever reason, Macchio and Mackie decided to flip-flop (not for the first time) and return Cletus once more to his former symbiotic Carnage glory. Thus, in Webspinners Tales of Spider-Man #14, Kasady fell into the negative zone, where he discovered a different symbiote, that in all ways appeared and acted just as his former one did. How convenient!
However, it seems that Peter Milligan, writer of the currently in-progress Venom/Carnage story didn't actually read his Carnage back-history properly, since his entire tale is heavily dependent on the Carnage symbiote being the spawn of the Venom symbiote. Unfortunately, as we dedicated SpiderFans know, he is sadly mistaken in this critical detail. Worse, it seems like nobody told Venom either.
As for the "Father's Day" reference, you might not know that greeting card companies in the United Kingdom, Australia and New Zealand celebrate Father's Day on September 5th, since this allows them time to package up any cards not sold during June in America and ship them overseas for resale.