The Hours of Prayer for the Old Covenant Church in the 1st century AD

The first hour of prayer:

9AM is the first hour of prayer [see Acts 2:15] when the Temple gates opened.  The Hebrew word for this hour of prayer is "Shacharit"(morning).  According to Jewish time this is the 3rd hour (the third hour from sunrise); according to Roman time this is the 9th hour (Roman time for each day began at 12 midnight).

The second hour of prayer:

3PM is the second hour of prayer [Acts 3:1; 10:9]. The Hebrew word for this hour of prayer is "Minchah" (gift-offering).  This hour of prayer was known as the "hour of confession."  The next day began at sundown, or about 6PM.  According to Jewish time this is the 9th hour; according to Roman time this is the 15th hour.

Michal Hunt, Copyright © 2005 Agape Bible Study. Permissions All Rights Reserved.

 Notice that the Jewish hours of prayer correspond to the crucifixion of Jesus Christ.  According to St. Mark, Jesus went to the cross at the third hour, which in Jewish time corresponds to our 9AM [Mark 15:25].

The Hebrew word for the third hour of prayer is "Ma'ariv"
"Ma'ariv" or evening prayer began at sundown [hours of prayer see Mishnah Berakhot].  According to the Jewish Book of Why, volume I the "Ma'ariv" is a later addition, after the destruction of the Temple in 70AD.  The Jewish Talmud records the late addition of the Ma'ariv service which is not connected with the sacrificial system. [Jewish Book of Why, volume I, page 148].