ARYABHATA-I ARYABHATEEYA (499 AD)
Ku ngi si bu nlru shru khru praak
Eastward rotations of the earth in one Yuga is 1582237500
Anuulomagathirnoustha: pasyathyachalam vilomagam
yadvath achalaani bhaani thadvath samapaschimagaani lankaayaam
Just as a man in a boat moving forward sees the stationary objects as moving backward,
so are the stationary stars and celestial bodies seen by the people at equator (Lanka) as moving exactly towards west.
Ku aavarthaaschaapi naakshathraa:
The rotation of the earth is the cause of days (Aryabhateeyam 3-5).