Srimad-Bhagavatam: Canto 5 - Chapter 1 - Verse 5
Sanskrit:
यदा वृश्चिकादिषु पञ्चसु वर्तते तदाहोरात्राणि विपर्ययाणि भवन्ति ॥ ५ ॥
ITRANS:
yadā vṛścikādiṣu pañcasu vartate tadāho-rātrāṇi viparyayāṇi bhavanti.
Translation:
When the sun passes through the five signs beginning with Vṛścika [Scorpio], the duration of the days decreases [until Capricorn], and then gradually it increases month after month, until day and night become equal [in Aries].