. Celebration of the landing of the Pilgrims at Plymouth on 11 Dec. 1620, o.s., inaccurately
converted to 22 Dec., N.S., when celebration of the anniversary began at Plymouth
in 1769. Only ten days should have been added (William Bradford, History of Plymouth Plantation, 1620–1647
, Boston, 1912, 1:176–177, note 2).