Yesterday's Weekend section listed wrong dates for the George Washington's Birthday celebrations in Alexandria. The afternoon of entertainment at the Bicentennial Center is Saturday, 1 to 3. The Revolutionary War encampment at Fort Ward will be Sunday at 11 a.m., with a skirmish at 2 p.m. The Washington Camerata performs at the Lyceum Sunday at 3 p.m. On Monday, the guided walking tour of Old Town will leave from Ramsay House at 11 a.m. and the parade will start at 2 p.m. A list of events can be obtained by calling 549-7268.

George Washington's 251st birthday will be celebrated this weekend with parades and exhibits all around Washington, not to mention sales and a day off. Here's a roundup of activities and special events celebrating the President's Weekend.

DISTRICT OF COLUMBIA

On Tuesday, there'll be a wreath-laying ceremony at the Washington Monument starting at 11. Military bands will perform in honor of the first president. Call 426-6700.

MARYLAND

Sunday at 2:30, visit the Montpelier Cultural Arts Center where a George Washington Musicale will be performed by young musicians playing colonial-style instruments. The music selection will be popular songs of Washington's period. Tickets to this free performance are available at the arts center in Laurel. Call Mr. Walton at 779-2011.

VIRGINIA

Alexandria offers myriad activities for history buffs. Starting Friday at the George Washington Bicentennial Center (the Lyceum), 210 South Washington Street, there's an afternoon of entertainment for children and adults. From 1 to 3, there are puppet shows, candlemaking demonstrations and silhouette cuttings. Immediately following is a program highlighting the musical mode of the canal era of Washington's time. Local musicians will perform on colonial instruments such as the washboard, spoons and banjo.

Saturday brings us back to the days of the Revolutionary War as the First Virginia Regiment sets up a hillside skirmish against His Majesty's 71st and 64th Regiment of Foot, at Fort Ward in Alexandria. Beginning at 11, historians will portray the life of a revolutionary soldier. The battle reenactment starts at 2. Call 549-0205.

At the Lyceum in Alexandria, the Washington Camerate, appearing in period costume, will perform Renaissance, early Baroque and Medieval music with reproduction period instruments. Free.

Sunday in Alexandria offers even more entertainment in honor of Washington's birthday. There'll be a guided walking tour of Old Town, weather permitting. The tour leaves Ramsey House Visitors Center, 221 King Street, at 11, immediately following a free historical film on Alexandria. Purchase the $2 tickets at Ramsey House.

At 12:30, the Potomac English Handbell Ringers will give a bell-ringing concert with more than a hundred bells in four- and eight-part harmony at the Lyceum. Their repertoire includes arrangements from classical composers, folk songs, carols and a demonstration of change ringing.

The Alexandria George Washington Birthday Parade begins at 2 led by Super Bowl champion Washington Redskins' kicker Mark Moseley, with marching fife and drum corps, military bands, floats, drill teams and more. The show winds its way up South Fairfax Street, through historical Market Square in Old Town and down along South St. Asaph Street. Call 549-0205.

Gadsby's Tavern Museum and the Carlyle House are also open Sunday, 10 to 5. Admission to the museums is $1.50 for adults and 75 cents for students six to 17; under six, free. The boyhood home of Robert E. Lee is also open for tours.

Fredericksburg, the boyhood home of Washington, honors his birthday with half-price admissions to the city's historic attractions, including: the Mary Washington House, which will throw a birthday party; Kenmore, the house of Washington's sister, Betty; The Rising Sun Tavern, built by Washington's younger brother, Charles; and the James Monroe Museum, filled with memorabilia from Monroe's life and presidency. All historic attractions are open 10 to 4.

In Mount Vernon, the Mount Vernon Sports Complex, 2017 Belle View Boulevard, is having a George Washington Birthday Skate on Monday, 9:30 to 7:30. Admission is $3.25 for adults; $2.50 for children; skate rental is $1.25. Call 768-3223.

The Mount Vernon home of Washington is offering free admission on Monday. There'll also be wreath-laying ceremonies at his tomb Sunday, Monday, Tuesday and Thursday. Call 780-2000.