Early Bird

Early Bird is a trait in the Fallout: New Vegas add-on Old World Blues.

Effects
From 6AM to 12PM, you gain +2 to all SPECIAL stats but from 6PM to 6AM, you suffer -1 to all SPECIAL stats. It is somewhat mitigated by the Night Person perk (resulting in a +1 INT and PER at night), and synergizes extremely well with Solar Powered (+2 Strength while in sunlight).

Behind the scenes
This trait is a modification of Night Person, which appears in Fallout and Fallout Tactics, and became a perk in Fallout 3 and Fallout: New Vegas.