Division of Time in ancient Indian time -
1 Thithi = 60 Ghatigalu
1 Ghatika (Ghati) = 60 Palagalu (Vighati)
1 Pala (Vighati) = 60 Vipala
1 Vipala = 60 Prativipala
Conversion -
1 Prativipala = 0.006 seconds
1 Vipala = 0.4 seconds
1 Vighati = 24 seconds
1 Ghati = 24 minutes
Also, 1 Muhoorta = 2 Ghatis = 48 mins
Also, 1 Thithi = 2 Karanas
Pradosha kala = 4 Ghatis before and after sunrise
= 40 mins before and 48 mins after sunrise.
1 Mahayuga = 10 Yugas
= Krutayuga (4 Yuga in length)
+ Tretayuga (3 Yuga)
+ Dwaparayuga (2 Yuga)
+ Kaliyuga (1 Yuga)
= 4320000 years
1 Yuga = 432000 years
1 Manvantara = 71 Mahayugagalu = 30,67,20,000 years
1 Brahma dina = 14 Mavantara (994 Mahayugagalu)
= 4,29,40,80,000 years
Vedas also say that before and after each Manvantara there is a gap equivalent to 4 Yugas apart from the Mahayuga.
So 1 Brahma dina = 14 Manvantaras + (15 x 4 Yugas)
= 994 Mahayuga + 60 Yugas
= 994 Mahayuga + 6 Mahayuga
= 1000 Mahayugas
= 4,32,00,00,000 years
Same with 1 Brahma Rathri - 1000 Mahayugas
1 Brahma poorna dina = 2000 Mahayugas
= 8,64,00,00,000 years
= 864 koti varshagalu.
1 Kalpa = 1 Brahma Poorna Dina
1 Brahma varsha = 360 Kalpa (Brahmadinagalu)
Our Universe exists for 100 Brahma varsha galu.
By the way, Universe translates to Uni-verse = OM.
Currently,
Our Brahma is 51 years old and 7th Manvantara of this Brahma dina.
If this is 7th Manvantara of current Brahma dina, we have 6 already passed.
That is, 426 Mahayugas have passed. And between 7 manvantaras, as mentioned abouve, we have 4 yuga gap between each of them. That accounts to 7 x 4 = 28 yugas or 2.8 Mahayugas.
In all, 428.8 mahayugas have passed till date for the current Brahma dina.
Also, we are now in 28th Manvantara (Vaivasvata Manvantara).
And kaliyuge prathama pade = 1/10th part to be added = 27.9 Mahayugas.
So in all, we can say it is 456.7 Mahayugas have passed.
That is 456.7 x 4320000 = 1,97,29,44,456 years have passed since the creation of current universe = Approximately 2 billion years (matches what science offers as the Universe's age).