SB 5.21.18

tathānye ca ṛṣayo gandharvāpsaraso nāgā grāmaṇyo yātudhānā devā ity ekaikaśo gaṇāḥ sapta caturdaśa māsi māsi bhagavantaṁ sūryam ātmānaṁ nānā-nāmānaṁ pṛthaṅ-nānā-nāmānaḥ pṛthak-karmabhir dvandvaśa upāsate.
Synonyms: 
tathā — similarly; anye — others; ca — also; ṛṣayaḥ — saintly persons; gandharva-apsarasaḥ — Gandharvas and Apsarās; nāgāḥ — Nāga snakes; grāmaṇyaḥ — Yakṣas; yātudhānāḥ — Rākṣasas; devāḥ — demigods; iti — thus; eka-ekaśaḥ — one by one; gaṇāḥ — groups; sapta — seven; caturdaśa — fourteen in number; māsi māsi — in every month; bhagavantam — unto the most powerful demigod; sūryam — the sun-god; ātmānam — the life of the universe; nānā — various; nāmānam — who possesses names; pṛthak — separate; nānā-nāmānaḥ — having various names; pṛthak — separate; karmabhiḥ — by ritualistic ceremonies; dvandvaśaḥ — in groups of two; upāsate — worship.
Translation: 
Similarly, fourteen other saints, Gandharvas, Apsarās, Nāgas, Yakṣas, Rākṣasas and demigods, who are divided into groups of two, assume different names every month and continuously perform different ritualistic ceremonies to worship the Supreme Lord as the most powerful demigod Sūryadeva, who holds many names.
Purport: 

In the Viṣṇu Purāṇa it is said:

stuvanti munayaḥ sūryaṁ
 gandharvair gīyate puraḥ
nṛtyanto ’psaraso yānti
 sūryasyānu niśācarāḥ

vahanti pannagā yakṣaiḥ
 kriyate ’bhiṣusaṅgrahaḥ
vālikhilyās tathaivainaṁ
 parivārya samāsate

so ’yaṁ sapta-gaṇaḥ sūrya-
 maṇḍale muni-sattama
himoṣṇa vāri-vṛṣṭīṇāṁ
 hetutve samayaṁ gataḥ

Worshiping the most powerful demigod Sūrya, the Gandharvas sing in front of him, the Apsarās dance before the chariot, the Niśācaras follow the chariot, the Pannagas decorate the chariot, the Yakṣas guard the chariot, and the saints called the Vālikhilyas surround the sun-god and offer prayers. The seven groups of fourteen associates arrange the proper times for regular snow, heat and rain throughout the universe.