Was the true Nissan 1 on April 14th this year?  The maturing of the first barley may have moved the date to April 14th.  That would put Resurrection Sunday on May 2nd and Pentecost on June 20th (a Sunday this year, and the last possible date for a spring Pentecost).  It also moves Rosh Hashanah forward four weeks, which would be next weekend!  This would be the last possible time for Rosh Hashanah to occur in any year, and provides an interesting count relative to the dates in the fall of 2017.