Shiva Purana
ब्रह्मविष्णुमहेशानां स्वस्वायुर्दिनमुच्यते । तदूर्ध्वं न दिनं रात्रिर्न जन्ममरणादिकम् ८८ ।
The span of life of Brahmā, Viṣṇu and Maheśa is a day. Beyond that, there is neither day nor night, neither birth nor death.
english translation
brahmaviSNumahezAnAM svasvAyurdinamucyate । tadUrdhvaM na dinaM rAtrirna janmamaraNAdikam 88 ।
hk transliteration by Sanscript