The phrase "thirteenth year" typically refers to someone's thirteenth birthday or the year they turn thirteen. It signifies the transition from childhood to being a teenager. Full definition
And Finally, as it slips in to it's thirteenth year Call of Duty is still the biggest thing ever and had a record monthly active user base in November and December 2015. (thesixthaxis.com)
The project known as Evangelicals and Catholics Together is now in its thirteenth year, following its initial statement, «The Christian Mission in the Third Millennium,» with much - discussed statements on salvation, Scripture, and the Communion of Saints. (firstthings.com)
The word of the Lord came to him, repeatedly: in the days of Josiah (the thirteenth year of his reign), in the days of Jehoiakim, and in the days of Zedekiah (Jer. (religion-online.org)