Can you get the old event Pokemon again without cheating?

Question

For Pokémon obtained in Generation IV onwards, the dates do not need
to be the dates the events were held. This is because the date is
based on the one set on the DS.

Source

Is this true and is IV 4 or 6?

Answer 1

That's true, but is does not mean you can get old event Pokemon at all. They are distributed by Nintendo whether it be through Wifi or a real-life event, the game doesn't "know" the dates. This is why it says "searching for gifts"; it is checking the servers for a gift. So changing the date won't do anything.

And IV in Gen 4. They are Roman Numerals, so that means:

I = Gen 1
II = Gen 2
III = Gen 3
IV = Gen 4
V = Gen 5
VI= Gen 6
VII = Gen 7
VIII = Gen 8
and so on.