In 2021, Pope Francis declared the fourth Sunday in July as World Day for Grandparents and the Elderly in the Church. The date was chosen to be near the liturgical memorial (July 26) of Saints Anne and Joachim, grandparents of Jesus.
Due to the secular celebration of Grandparents Day in the United States, the Administrative Committee of Bishops transferred the Church’s celebration to coincide with that of the nation’s on the Sunday after Labor Day in September.
Since 1978 many American local communities, schools, and parishes have been accustomed to observing the September celebration. That said, it is appropriate to include grandparents and the elderly in NFP Week celebrations.
See what activities you can take part in through the United States Conference of Catholic Bishops website:
https://www.usccb.org/topics/natural-family-planning/nfp-week-celebrates-grandparents