'Seventh' in the Bible

"Say to all the people of the land and to the priests: 'When you fasted and lamented in the fifth and seventh months for these seventy years, did you really fast for me?

"Thus says Yahweh of hosts: 'The fast of the fourth [month], the fifth [month], the seventh [month], and the tenth [month] will be for the house of Judah jubilation and joy and merry festivals; therefore love truth and peace.'