SB 5.1.31

The troughs created by the wheels of his chariot produced seven oceans, from which seven continents were formed. The movement of the wheel of his chariot produced troughs which became seven oceans. This means that he had seven chariots each with one wheel, by the power of his yoga. Their movement was higher than the sun’s, and they circled around the plane of the earth. Jīva Gosvāmī says in the Sandarbha that one should understand that the chariots were successively larger and larger in size, since the outer circles were larger and larger. Some say that he made larger and larger chariots in succession, each one twice the size of the previous one, traveling higher and higher so that the inhabitants of his city in Āryāvarta could see his chariot even at a great distance. Because the wheels of each chariot were broader than the previous ones, the oceans were successively broader. He rode in each of these seven chariots for twenty-five days and forty-five and a half ghaṭikas each (totaling half a year), starting with the summer equinox, with the sun gradually descending until Pauṣa month. Then again starting from the winter equinox, he would travel until the cycle was completed, with the same number of days fixed, but with the opposite order of chariots, with the sun gradually ascending until Aṣaḍha month. As the sun traveled around Meru clockwise along with the dependent zodiac, it gradually increased in speed, [Note: This would apply relative to Āryavarta. It would gradually speed up during each rotation when it came to Āryavarta and slow down in the opposite area behind Meru. The accelerated section (and decelerated section) would gradually shift around Meru during the year. ] and thus the days after the summer equinox become shorter each month, and from the winter equinox the sun gradually slowed down and the days become longer. In order to decrease the night, Priyavrata by his own will circled Meru, but slowing down his chariot increased the length of the days after the winter equinox, and then decreased the length of the days according to his will by speeding up his chariot. By the power of yoga, his chariots were visible or invisible according to the time. [Note: It appears from this description that before the time of Priyavrata the days and nights were equal, but by his will made the length of the days and nights change throughout the year. ] Thus “seven times” in the previous verse means that he traveled in seven chariots in the manner described above. There is no contradiction, since it is not proper to say that Priyavrata stopped pursuing the sun after only seven days, and some say he did not give up this activity. Because of these seven oceans (yataḥ), seven continents formed.