2 Chronicles 15:10

So they gathered themselves together at Jerusalem
By the order of Asa, ( 2 Chronicles 15:9 ) ,

in the third month;
of the ecclesiastical year, the month Sivan, in which month was the day of Pentecost; and that very probably was the time of their gathering:

in the fifteenth year of the reign of Asa;
and which seems to be the year in which he fought the Ethiopians.