Lexington will host its annual Patriots Day parade on Sunday, a day earlier than its traditional schedule, with the event also part of the celebrations marking the town’s 300th anniversary. The parade will begin at 2 p.m. at Massachusetts Avenue and Maple Street in East Lexington, and proceed to the town center before turning onto Worthen Road and ending at the town pool’s parking lot. On Monday at 5:30 a.m., historical reenactors will return to the town common to re-create the events of April 19, 1775. The Battle of Lexington reenactment typically draws thousands of spectators to the town green and other historical sites in the area. Other Patriots Day weekend events include tours of the Buckman and Munroe taverns, and the Hancock-Clarke House. A reenactment of Paul Revere’s ride through Lexington will arrive at the Battle Green at about 1 p.m. Monday, and the Norwich University Regimental Band and Drill Team will perform on the Battle Green at 2 p.m.