Srimad Bhagavatam Canto 06, Chapter 06, Text 16

SB 6.6.16

vibhavasor asutosa
 vyustam rocisam atapam
pañcayamo ’tha bhutani
 yena jagrati karmasu
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Usa, the wife of Vibhavasu, gave birth to three sons — Vyusta, Rocisa and Atapa. From Atapa came Pañcayama, the span of day, who awakens all living entities to material activities.
Srimad Bhagavatam Canto 06, Chapter 06, Text 15
Srimad Bhagavatam Canto 06, Chapter 06, Text 17-18