One verse

Srimad Bhagavatam 12.2.33

12.2.33

यस्मिन् कृष्णो दिवं यातस्तस्मिन्नेव तदाहनि । प्रतिपन्नं कलियुगमिति प्राहु: पुराविद: ॥ ३३ ॥

yasmin kṛṣṇo divaṁ yātas tasminn eva tadāhani pratipannaṁ kali-yugam iti prāhuḥ purā-vidaḥ

yasmin
on which
kṛṣṇaḥ
Lord Śrī Kṛṣṇa
divam
to the spiritual world
yātaḥ
gone
tasmin
on that
eva
same
tadā
then
ahani
day
pratipannam
obtained
kali-yugam
the Age of Kali
iti
thus
prāhuḥ
they say
purā
of the past
vidaḥ
the experts

Those who scientifically understand the past declare that on the very day that Lord Śrī Kṛṣṇa departed for the spiritual world, the influence of the Age of Kali began.