Up and down the hills of West Bethesda, running, trotting, walking fast, postman Lance Beets ignored the dogs that barked at him, never complained about the lack of tips coming his way and whistled continually as he moved along.

But now, as he opened still another mailbox, he groaned. Inside it were two Christmas cards addressed to people in New York.

"Oh God," he said, a breif look of disgust replacing his perpetual smile.

"Two days before Christmas and they're just sending cards. What a bummer. These things will get delivered next week and some poor mailman will get yelled at.

"Oh well, it's the last day, I'm not going to get up tight."

For Beets and thousands of other letter carriers around the country, yesterday was "The Last Day!"

The last day of a month of carrying double and triple loads, of working twice as hard as normal and knowing that a delay could cost someone a Christmas present.

It was also the last day to receive Christmas tips and Beets, who has been on his route for only one year, has not been raking it in.

"Some of the guys who have been on the same route for 10 or 15 years just clean up at Christmas," he said. "Some of them make more than $1000. Me, I'm glad for what ever I get."

Some mail carriers may grumble about those who do not take care of them at Christmas, but not Beets, who is 29, "I don't worry about it," he said, grinning behind the blond beard and mustache that hide much of his face."I remember once I asked my mother if she tripped her mailman and she said 'hell no, why should I?'"

The month of December is to the post office what April 15 is to the IRS. No annual leave is granted during the entire month. Long hours of overtime are put in. And, in spite of the constant pleas to "mail early," it is not unusual for letters that belong in New York to be in Bethesda on Dec. 23.

"Sure, there's more to do," he said, as he sorted his mail at 8:30 a.m. yesterday. "I've got twice as much here as usual. It's been that way all week.

"But when I get out there, I see more people than usual. They stop to wish me Merry Christmas or to thank me. That's nice. Those envelopes (tips) are nice, too, though."

As he walked his hilly route yesterday, his right shoulder sagging slightly under the weight of his mail, Beets whistled Christmas songs, had a wave, a smile or a greeting for everyone he met, and never lost his smile or his somewhat wacky, Steve Martin like sense of humor.

"This time of year if you start taking yourself seriously you'll just get depressed," he said, sweating slightly as he kept up a breakneck pace. "What's the point. You have to try and have fun whenever you can-right?"

Does anything exciting ever happen while he delivers the mail? "If you mean do I ever get attacked by nude women at the door? No, unfortunately, nothing like that ever happens," he said in his best comic voice."But you neverknow what lies ahead." He dissolved in laughter.

As Beets was loading his mailtruck yesterday, a steady trickle of customers was keeping the clerks inside the West Bethesda substation at 9601 Seven Lock Rd. occupied, but not overly busy.

"We've been fairly quiet since Thursday," station manager DickAger said. "Most people are out shopping for relatives by now."

But while things had quieted inside the station, Beets and the other carriers were hurrying through the final hours before Christmas.

"I'll get through this knowing there's a Christmas party back at the station waiting for me," Beets said. "You don't want to be out here all day and have nothing but stale bread left when you get in."

And so Beets completed his appointed rounds in about three hours, picking up several envelopes, two packages and one plate of cookies along the way.

Then it was back to the station for the party, and home to his wife for Christmas and two days of relaxation.

"Next week is worse," he said. We have to deliver all the post-Christmas junk mail. At least this way I'm delivering stuff people want. You don't feel like yelling (Merry Christmas,' when you're stuffing junk in their boxes.

"But, there's always next year, right?"