'Seventh Day' in the Bible

Now in the fifth month, on the seventh day of the month, which was the nineteenth year of king Nebuchadnezzar, king of Babylon, came Nebuzaradan the captain of the guard, a servant of the king of Babylon, unto Jerusalem.

Now it came about in the thirty-seventh year of the exile of Jehoiachin king of Judah, on the twenty-seventh day of the twelfth month, that Evil-merodach king of Babylon, in the year that he became king, showed favor to Jehoiachin king of Judah and released him from prison;