The daughters of Prajapati (Samvatsara) are considered the controlling deities of the nights, and his sons are considered the controllers of the days

Expressions researched:
"The daughters of Prajapati are considered the controlling deities of the nights, and his sons are considered the controllers of the days"

SB Canto 5

The daughters of Prajāpati are considered the controlling deities of the nights, and his sons are considered the controllers of the days. The Prajāpati's offspring number 36,000, one for each day and each night in the lifetime of a human being. At the end of each year, the Prajāpati's daughters become very agitated upon seeing the extremely effulgent disc of the Supreme Personality of Godhead, and thus they all suffer miscarriages.

SB 5.18.15, Translation and Purport:

Śukadeva Gosvāmī continued: In the tract of land called Ketumāla-varṣa, Lord Viṣṇu lives in the form of Kāmadeva, only for the satisfaction of His devotees. These include Lakṣmījī (the goddess of fortune), the Prajāpati Saṁvatsara and all of Saṁvatsara's sons and daughters. The daughters of Prajāpati are considered the controlling deities of the nights, and his sons are considered the controllers of the days. The Prajāpati's offspring number 36,000, one for each day and each night in the lifetime of a human being. At the end of each year, the Prajāpati's daughters become very agitated upon seeing the extremely effulgent disc of the Supreme Personality of Godhead, and thus they all suffer miscarriages.

This Kāmadeva, who appears as Kṛṣṇa's son named Pradyumna, is viṣṇu-tattva. How this is so is explained by Madhvācārya, who quotes from the Brahmāṇḍa Purāṇa: kāmadeva-sthitaṁ viṣṇum upāste. Although this Kāmadeva is viṣṇu-tattva, His body is not spiritual but material. Lord Viṣṇu as Pradyumna or Kāmadeva accepts a material body, but He still acts spiritually. It does not make any difference whether He accepts a spiritual or a material body; He can act spiritually in any condition of existence. Māyāvādī philosophers regard even Lord Kṛṣṇa's body as material, but their opinions cannot impede the spiritual activity of the Lord.