2 Chronicles 35:1

Moreover, Josiah kept a passover unto the Lord in Jerusalem ,.... Where only it was to be kept:

and they killed the passover on the fourteenth day of the first month ; the month Nisan, as the Targum, which was the exact time of killing the passover lamb, according to the law of Moses, Exodus 12:6 , in the Vulgate Latin version of the Apocrypha in:"And Josias held the feast of the passover in Jerusalem unto his Lord, and offered the passover the fourteenth day of the first month;' (1 Esdras 1:1)it is called the fourteenth moon of the first month; a phrase often used in ecclesiastical writers, when speaking of the time of the passover; and so we now call one of the days of the week "dies lunae", Monday.