'Seventh' in the Bible

Speak unto all the people of the land, and to the priests, saying, When ye fasted and mourned in the fifth and in the seventh month , even these seventy years, did ye at all fast unto me, even to me?

Thus saith Jehovah of hosts: The fast of the fourth month , and the fast of the fifth, and the fast of the seventh, and the fast of the tenth, shall be to the house of Judah joy and gladness, and cheerful feasts; therefore love truth and peace.