The Yoga of the Imperishable Absolute

Krishna describes the vast time scales: 'Sahasra-yuga-paryantam ahar yad brahmano viduh'—those who know (viduh) the day (ahar) of Brahma (brahmanah), which lasts (paryantam) a thousand (sahasra) yugas (yuga). 'Ratrim yuga-sahasrantam te 'horatra-vido janah'—and the night (ratrim) which also lasts a thousand yugas (yuga-sahasra-antam), those (te) people (janah) are knowers (vido) of day and night (ahoratra). This verse introduces the cosmic time scale: Brahma's day lasts a thousand yugas, and his night also lasts a thousand yugas. This is the vast cycle of creation and dissolution. Understanding this helps you realize the scale of material existence—even the highest material worlds exist within these vast cycles. This sets up the teaching about the cycles of creation and dissolution (verses 8.18-8.19).