Daniel 9:1-3 World English Bible (WEB)
9 In the first year of Darius the son of Ahasuerus, of the offspring of the Medes, who was made king over the realm of the Chaldeans, 2 in the first year of his reign I, Daniel, understood by the books the number of the years about which Yahweh’s word[a] came to Jeremiah the prophet, for the accomplishing of the desolations of Jerusalem, even seventy years. 3 I set my face to the Lord God, to seek by prayer and petitions, with fasting and sackcloth and ashes.
Daniel 9:1-3 New International Version (NIV)
9 In the first year of Darius son of Xerxes[a] (a Mede by descent), who was made ruler over the Babylonian[b] kingdom— 2 in the first year of his reign, I, Daniel, understood from the Scriptures, according to the word of the Lord given to Jeremiah the prophet, that the desolation of Jerusalem would last seventy years. 3 So I turned to the Lord God and pleaded with him in prayer and petition, in fasting, and in sackcloth and ashes.