The early church recognized three additional hours of personal prayer in the day that all Christians were to observe. These hours of prayer were maintained by the ethnic Orthodox churches, Roman church and Anglican church. For some reason, as the Reformation gained speed, these hours of observance fell more and more into obscurity. Personally, I think it is the duty of any Christian who seeks continuity with the church of the Apostolic and post-Apostolic eras to resurrect these hours of prayer as a faithful observance.
“Those who know the blessed triad of the holy abodes, are acquainted with the distribution of the hours into a three-fold division.”- Clement of Alexandria
“As for times of prayer, nothing at all has been prescribed except clearly “to pray at every time and place”...However, the outward observance of certain hours will not be unprofitable. I mean those common hours that mark the intervals of the day- the third, sixth and ninth- which we may find in the Scriptures to have been more solemn than the rest.”- Tertullian
“..we also pray at a minimum of not less than three times during the day. For we are debtors to Three: Father, Son and Holy Spirit.”- Tertullian
“In Luke's writings, the third hour is demonstrated as an hour of prayer. It was about this time that those who had received the inaugural gift of the Holy Spirit were thought to be drunkards. And then there is the sixth hour, at which hour Peter went up on the roof. Finally there is the ninth, at which hour they entered the temple. Why should we not understand that, with absolute perfect indifference, we must pray always, everywhere, and at every time? Still, these three hours are distinguished in human affairs.”- Tertullian
“Offer up your prayers in the morning, at the third hour, the sixth, the evening and at cock-crowing.” - Apostolic Constitutions
These are times in which we offer as individuals and/or families our personal prayers and worship to God. There is no prescribed prayer for these hours since they are personal, and these prayers are not communal. These prayers are to be said facing the east, toward Jerusalem, the Holy Land, where our Lord lived and ultimately gave His life for us, and shall return to.
“..prayers are made looking toward the sunrise in the east.”- Clement of Alexandria
These hours of prayer are:
Terce (The Third Hour)- Observed at 9 a.m.
Sext (The Sixth Hour)- Observed at 12 p.m.
None (The Ninth Hour)- Observed at 3 p.m.