Since he took over as coach of the Washington Capitals two years ago, Tom McVie has rigidly enforced an 11 p.m. curfew on nights before games.

He has prowled popular watering places, opened hotel doors on the road, called players at their homes here, all in the interest of proper preparation.

So what did the Capitals do last night? En masse, led by McVie, they violated that curfew less than 24 hours before they play the Boston Bruins at 7:30 tonight at Capital Centre.

"I could catch them all for being out after 11 and really rake in some money," McVie said with a laugh before revealing the reason for the aberration.

The Capitals, from 10:30 p.m. to midnight, were practicing at Fort Dupont.

The last time McVie scheduled an evening practice session was in January, 1976, at Bloomington, Minn. That time the NHL Players Association expressed objection, on behalf of aggrieved Capitals. This time, however, there will be no complaint.

By agreement with the Players Association, teams are forbidden to schedule games or practices on Christmas Eve or Christmas Day. Many of the Capitals took advantage of the hiatus to celebrate at their homes in Canada, but the airline schedules made a return for yesterday's regular 10 a.m. practice a problem.

"I guess I must be softening up," McVie said. "Instead of just telling them to be there in the morning, I decided to have a vote. It was either 10 a.m. or 10:30 p.m., because the rest of the day the rink was taken by public skating.

"There's been some talk about our three days in Squaw Valley bringing the team together. Well, I guess it did. Before Squaw Valley, the guys living around here probably would not have been concerned about those guys. They would not have practiced late at night, but they all agreed to do it, so the guys could go home."

The practice is just one of several odd circumstances surrounding tonight's contest with the Bruins.

Washington general manager Max McNab has been entertaining his family this weekend, and one member is center Peter McNab of the visiting Bruins.

Petr brought his wife here and will remain in his father's home until his teammates arrive for this morning's practice at Capital Centre.

"There hasn't been a lot of hockey talk," the elder McNab said. "We got out the old home movies for Peter's bride. She had never seen him in the bathtub as a 2-year-old."

For those who haven't seen women play ice hockey, an early visit to Capital Centre is advised. The Washington women's team. based at Tyson's Rink, will play a club from Nashua, N.H., at 5 p.m.

Although Capital Centre ticket wickets do not normally open until 6:30, fans arriving as early as 5 o'clock may purchase tickets at t the Capital Centre through the administrative entrance.

The oddest circumstance. if it should develop, would be a victory for the Capitals. In 16 meetings with the Bruins, Washington has not won. The Caps have produced three ties.

A month ago in Boston, the Capitals were wiped out, 6-0, but they have since revised their act, winning four and tying one in their last seven games.

Boston, however, has shown no sign of deterioration. The Bruins, who share the Adams Division lead with Buffalo, have lost only two of their last 22 games and whipped Philadelphia, 6-1, in their last start.

The Capitals are still working with three goaltenders and McVie was waiting until today to pick tonight's starter. The likely choice against the forechecking Bruins, who apply tremendous pressure to both defense and goalie, is Jim Bedard, a superior puck handler.