In the Bible, what year is the slaughter of the innocents at Bethlehem purported to have taken place?

I have it on good authority that Herod died in March of 4 b.c.e. (that is, March of 4 B.C..) and several possible years for Jesus’ birth
(I personally believe that it was during the Feast of Tabernacles in 5 b.c.e. but could be wrong).

My question is, when did the Magi arrive and Herod order the slaughter of the babies under two years old in Bethlehem?

I am not asking IF it happened— I am asking when it is said or believed to have occurred, given the fairly certain date of March in 4 b.c.e. for Herod’s death. and Jesus’ birth a year or two thereabout before