As mentioned in the previous verse (BG 8.17–8.19), one day of Brahma lasts one thousand cycles of the four yugas.
1000 cycles of the four yugas is:
1000 x (1.728 + 1.296 + 0.864 + 0.432) Million
= 1000 x (4.32 Million)
= 4320 Million
= 4.32 Billion years
Thus one day (12 hours) of Brahma is 4.32 Billion Earth years, and one night (12 hours) of Brahma is 4.32 Billion Earth years, and he lives for 100 of his years, which is 311 trillion, 40 billion years for us.
4.32 Billion x (night and day) x (30 days in a month) x (12 months in a year) x 100 years
That is:
4.32 Billion x 2 x 30 x 12 x 100 = 311 trillion, 40 billion years
Just think how fantastic the life of Brahma is compared to us, but even he has to die one day and he has already lived for 155.522 trillion years, this is his current age and half his long life is over. We live a very short life of at most 100 years and should realize that this material life is meant for spiritual realization and not material accumulation and attachments.
We are working like donkeys to accumulate properties, and bank balances, but this is all a complete waste of life. If we don’t use our time, energy, and wealth in the service of Lord Krishna.
