Sometimes messing with your DS clock can result in game play changes. I would leave your DS for a day and try again, since after your DS adjusts to the time change, game play should return to normal.
If this is Gen V, your DS is in October and the game itself should be in summer, which means "night" is shorter (goes from about 10pm to 4am). And yea, 22:00 is 10pm.
Issues like this will arise if your Gligar is hacked/ illegitimately obtained.
Also, just double check that Gligar is holding Razor Fang and not Claw; it's an easy enough mistake.