Ūrja (Urja) denotes the month of Kārtika (Kartika). According to Bhāgavatapurāṇa (Bhagavatapurana), in this month, Udita Sūrya (Udita Surya; the risen Sun) is called Viṣṇu (Vishnu). In this month, the Nāga (Naga, Snake) called Aśvatara (Aswatara), Rambhā, the Apsarā (Apsara; Celestial Courtesan), the Gandharva (One kind of demi-god) named Sūryavarcā (Suryavarcha), the Yakṣa(Yaksha; one kind of devine being) named Satyajit, Ṛṣi (Rishi; Sage) Viśvāmitra (Viswamitra) and the Rākṣasa(Rakshasa; one kind of demon) called Makhāpeta (Mahapeta) stay in the chariot of the Sun-god.
In Vāyupurāṇa (Vayupurana), a different description is found. According to Vāyupurāṇa, in the months of Āśvina (Aswina) and Kārtika, the Āditya(s) called Parjanya and Pūṣā (Pusha), the sages Bharadvāja (Bharadwaja) and Gautama, the Gandharvas called Viśvāvasu (Viswavasu) and Surabhi, the Apsarās called Viśvāci (Viswachi) and Ghṛtāci(Ghritachi) , the Nāgas called Airāvata (Airavata) and Dhananjaya (Dhananjaya), the Yakṣas called Senajit and Suṣeṇa (Sushena) and the Rākṣasas called Āpa (Apa) and Vāta(Vata) stay in the chariot of the Sun-god.