The reign of Joram

• Jehoram (King of Judah and son of Jehoshaphat)

• Start — no reference given. The year Jehoram's regency began is the year Jehoshaphat's reign began (3093) + 16 years = 3109
• End — 2 Kings 8:17. The year Jehoram's reign ended is the year his reign began (3114) + the length of his reign (8) - a 1-year duration overcount = 3121

"In the eleventh year." That is to say, after the eleventh year, for he became king in the twelfth year, as we read above: (2KI 8:25): "In the twelfth year of King Joram..." For his father Joram became king in the fifth year of Joram son of Ahab, and he reigned for eight incomplete years, ending in the twelfth year of Joram son of Ahab, when Ahaziah became king. (Mezudat David) Shulman, p122

Years are anno hominis — counted from Creation as year 1 — which is the frame the source computes in. The arithmetic behind each boundary is given above rather than assumed.