According to Wikipedia:
The modern Jewish Passover and Feast of Unleavened Bread is seven days, starting with the sunset at the beginning of Nisan 15.
According to some interpretations, the Gospel of John (e.g., 19:14, 19:31, 19:42) implies that Nisan 14 was the day that Jesus was crucified in Jerusalem.
The article mentions that this was the first Easter controversy which petered out around the 4th century and that "Jehovah's Witnesses continue to celebrate the memorial of Christ's death on Nisan 14."
Recently, an answer on Biblical Hermeneutics asserted that Jesus was crucified on Nisan 14. This indicates the interpretation is still supported in some modern traditions.
Are there any denominations that interpret John 19 as placing the crucifixion on Nisan 14? Do the Jehovah's Witnesses base their memorial on John 19?