If I recall correctly, the date was the first week in June and then moved up earlier for school graduation conflicts one year and it has not returned to the later date. I liked it better after Memorial Day due to traffic issues on the roads.
Sometime life gets in the way of living.......
Last rally I attended was 2016 and I recall Tammy saying that it wasn't going to be moved back to June at NK' Mip's request. I also believe that she said that in the future it would be scheduled for the last full weekend in May.
What a long strange trip it’s been!