There is much debate and division regarding when Passover is to be observed. The author of the link below shares my view in the timing, but he references Passover as a celebration of the Jews. Scripture calls it the Passover of YHWH, and is to be remembered for all generations by His people. Therefore; Passover is to be observed in remembrance by all the children of YHWH.
http://www.bibletrack.org/notes/resource/misc/Passover_day.html
