Bells will ring throughout town Sunday evening to celebrate Lexington’s 300th anniversary. The official observation of the town’s incorporation on March 31, 1713, will begin at the Old Belfry tower at 5:13 p.m. (which organizers point out is 17:13 in military time). Churches will be ringing bells along with the Old Belfry for five minutes, and residents are invited to step outside and ring a bell at the same time. The town’s 300th Anniversary Committee decided to hold the tercentennial LexCelebrate festival earlier this month to avoid any conflict with Sunday’s observances of Easter. Other events marking the milestone will continue through Memorial Day, May 27.