NASB 1995
and as they were returning, after spending the full number of days, the boy Jesus stayed behind in Jerusalem. But His parents were unaware of it,

American Standard Version
and when they had fulfilled the days, as they were returning, the boy Jesus tarried behind in Jerusalem; and his parents knew it not;

Berean Study Bible
When those days were over and they were returning home, the boy Jesus remained behind in Jerusalem, but His parents were unaware He had stayed.

Douay-Rheims Bible
And having fulfilled the days, when they returned, the child Jesus remained in Jerusalem; and his parents knew it not.

English Revised Version
and when they had fulfilled the days, as they were returning, the boy Jesus tarried behind in Jerusalem; and his parents knew it not;

King James Bible
And when they had fulfilled the days, as they returned, the child Jesus tarried behind in Jerusalem; and Joseph and his mother knew not of it.

World English Bible
and when they had fulfilled the days, as they were returning, the boy Jesus stayed behind in Jerusalem. Joseph and his mother didn't know it,

Young's Literal Translation
and having finished the days, in their returning the child Jesus remained behind in Jerusalem, and Joseph and his mother did not know,

Luke 2:43 Additional Translations ...