Prahars in Indian Classical Music

In Indian Classical Music, whole day(24 hours) is divided into 8 Prahars - 4 prahars of the day and 4 Prahars of the night.

The four Prahars of the day corresponds to-
Pehla Prahar 6:00 A.M. to 9 A.M is called Purvaanha
Doosra Prahar 9:00 A.M. to Noon is called Madhyaanha
Teesra Prahar Noon to 3:00 P.M. is called Aparaanha
Choutha Prahar 3:00 P.M. to 6:00 P.M. is called Saayankala

The four Prahars of the night corresponds to-
Pehla Prahar 6:00 P.M. to 9 P.M is called Pradosha
Doosra Prahar 9:00 P.M. to Midnight is called Nishitha
Teesra Prahar Midnight to 3:00 A.M. is called Triyaamaa
Choutha Prahar 3:00 A.M. to 6:00 A.M. is called Ushaa