From this the 'Hours' developed. The hours are the times when the liturgy is done. The first hour of the Jewish day is where the first liturgical hour is put, and this is called 'Prime' - at about 06.00 by our measurement of daily time. 3 hours later, at the third hour, the liturgical hour of 'Terce' is celebrated. 3 hours after that, the sixth hour, sext is celebrated.
None is celebrated at the ninth hour.
The evening hour is called 'Vespers', and the night hour called compline. Then there is matins. This is the early morning hour which consists of long readings. After this is the dawn hour called lauds - an acclamation of praise to God for the new day. Then were back to prime.