SB 3.7.33
sraddhasya ca vidhim brahman
pitrnam sargam eva ca
graha-naksatra-taranam
kalavayava-samsthitim
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Please also explain the regulations for offering respects to the forefathers, the creation of the Pitrloka, the time schedule in the planets, stars and luminaries, and their respective situations.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The time durations of day and night as well as months and years are different in the different planets, stars and luminaries. The higher planets like the moon and Venus have time measurements different from those of the earth. It is said that six months of this planet earth equal one day of the higher planets. In Bhagavad-gita the duration of one day in Brahmaloka is measured to be 1,000 times the four yugas, or 4,300,000 years multiplied by 1,000. And the month and year in Brahmaloka are calculated in that measure.