Mass. Gen. Laws ch. 6 § 12T
The governor shall annually issue a proclamation setting apart the fourteenth day of January as Albert Schweitzer's Reverence for Life Day, the third Monday of February as Washington's Day, the first Sunday in April as Veterans of World War I Hospital Day, the second Sunday in April as Aunt's and Uncle's Day, the fourth day of May as Horace Mann day, the second Sunday in May as Mother's Day, the third Sunday in June as Father's Day, the seventh day of August as Purple Heart Day, the first Sunday in October as Senior Citizens' Day, the first Sunday in December as Disabled American Veteran's Hospital Day and the second Saturday in December as Army and Navy Union Day; and recommending that said days be observed by the people in an appropriate manner.
Mass. Gen. Laws ch. 6, § 12T