Puran

1. Bhagavata Purana (1.18.6),
2. Vishnu Purana (5.38.8),
3. Brahmanda Purana (2.3.74.241),
4. Vayu Purana (2.37.422),^[7] and 
5. Brahma Purana (2.103.8) state that the day Krishna left the earth was the day that the Dvapara Yuga ended and the Kali Yuga began