Since 3/4 siblings in my famly are married, we often try to coordinate or plan Mother's and Father's Day in advance to accommodate all families.
It had been our plan (DH and I) to go to the cemetary on Father's Day. The cemetary is in NJ and then spend a couple hours with my family at my brother's house in Rockland - not too far away. Then we would go back to LI to be with DH's family.
I have come to learn that my father's yahrzeit (the religious commemoration of his passing according to the Hebrew calendar) is actually on Father's Day. It is so incredibly rare that this happens and may not happen again for another 10 or so years. It had been suggested 2 years ago by the Rabbi when Dad passed away, that we are together on this day. I have had only one Father's Day without Dad so far, but this one may be even harder than the first.