Srimad-Bhagavatam: Canto 12 - Chapter 1 - Verse 32
Sanskrit:
मध्वादिषु द्वादशसु भगवान् कालरूपधृक् ।लोकतन्त्राय चरति पृथग्द्वादशभिर्गणै: ॥ ३२ ॥
ITRANS:
madhv-ādiṣu dvādaśasubhagavān kāla-rūpa-dhṛkloka-tantrāya caratipṛthag dvādaśabhir gaṇaiḥ
Translation:
The Supreme Personality of Godhead, manifesting His potency of time as the sun-god, travels about in each of the twelve months, beginning with Madhu, to regulate planetary motion within the universe. Traveling with the sun-god in each of the twelve months is a different set of six associates.