Father's Day
Father's Day, is observed on the feast day of Fathers. It is celebrated as a public international day, like in many other countries including the U.S., on the third Sunday of June.
In Greece, like in other European countries, this day is named (Fête des Peres/Feast of Fathers)
National Grandparents Day
Congress passed the legislation proclaiming the first Sunday after Labor Day as National Grandparents' Day in the U.S. and, on August 3, 1978, then-President Jimmy Carter signed the proclamation.
The flower of the U.S. National Grandparents Day is the forget-me-not which blooms in the spring. As a result, seasonal flowers are given in appreciation to grandparents on this day.