Night Person (Fallout 3)

Night Person is a perk $$

Effects
With this perk, the player gains +2 to both Intelligence and Perception (up to a maximum of 10) between 6:00 P.M. and 5:59 A.M. in-game time.

As this perk only gives a temporary increase to the player character's statistics (unlike the Intense Training perk), it does not give an advantage when leveling up - there is no change to the number of skill points gained and the increased stats do not count for any perk requirements. Thus, the only effects are enhanced threat detection, Intelligence and Perception ability checks (in dialogue and elsewhere), and a bonus of +4 (or less if the player character's Perception and/or Intelligence is already higher than 8) to Medicine, Repair, Science, Energy Weapons, Explosives and Lockpick.