Pokemon Events 4th and 5th Generation
There are many tutorials online for accessing Nintendo DS game events; it's not very complicated. However, I always see that the tutorials recommend changing the console's date to the event's date. I apologize if this is a stupid question, but how does that affect Pokémon? I understand that a current date would mean "this Pokémon isn't from that event," but would the Pokémon be marked as illegal, causing problems in games? Or is it simply a recommendation (for example, would a Reggigigas from today's event mark it as illegal in PKHex?)