Wikipedia
National Good Neighbor Day is a national holiday in the United States. In 2003, the annual day of celebration was changed from the fourth Sunday in September to September 28.
In the early 1970s, Becky Mattson of Lakeside, Montana created National Good Neighbor Day as a day to connect with and recognize the importance of good neighbors. On September 22, 1978, President Jimmy Carter signed Proclamation 4601 establishing September 24, 1978 as National Good Neighbor Day, stating that it should be observed "with appropriate ceremonies and activities."
-----------
With that in mind I can only wonder at the inscription on the plaque- "Dedicated Good Neighbor Day May 16 1987". Was the date inscribed incorrectly or does Italy, TX celebrate a different "Good Neighbor Day".