Hey early risers! Enjoy a +2 to each of your SPECIAL attributes from 6 am to 12 pm, but suffer -1 from 6 pm to 6 am when you're not at your best.”— Fallout: New Vegas description
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 the trait Night Person which appears in Fallout and Fallout Tactics, and became a perk in Fallout 3 and Fallout: New Vegas.