Berean Standard Bible (BSB)
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.
World English Bible (WEB)
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,
Strong's King James
And{G2532} when they had fulfilled{G5048}{(G5660)} the days{G2250}, as{G1722} they{G846} returned{G5290}{(G5721)}, the child{G3816} Jesus{G2424} tarried behind{G5278}{(G5656)} in{G1722} Jerusalem{G2419}; and{G2532} Joseph{G2501} and{G2532} his{G846} mother{G3384} knew{G1097}{(G5627)} not{G3756} of it.
The F.O.G *
(43) In their turning back after completing the days, the boy Yeshua remained in Yerushalayim (Foundation of Peace) and His parents didn't know,
The F.O.G Message *
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,