Merry Christmas. No, honest, as in "the 12 days of" you know what between Dec. 25 and Jan. 5.

If you doubt the accuracy of this statement, you can head over to the website of the U.S. Conference of Catholic Bishops. There you will find an interactive calendar that bravely documents the fact that, according to centuries of Christian tradition, the quiet season called Advent has just ended and the 12-day Christmas season has just begun.

So cease stripping the decorations off your tree and postpone its premature trip to the curb. There is still time to prepare for a Twelfth Night party and then the grand finale on Jan. 6, when the feast of the Epiphany marks the arrival in Bethlehem of the magi.

"You would be amazed how hard it was to find information on the World Wide Web about all of this," lamented Joe Larson, the USCCB's director of digital media. "We wanted to link to sites that would help tell Catholics what we believe about these seasons and why we do what we do -- or what we are supposed to do -- during Advent and Christmas. ...

"What we ended up with is definitely not a finished product, but we'll expand it in the future. We got the ball rolling this year."

The materials gathered at www.usccb.org/advent do not, at first glance, appear to be all that rebellious.

The website contains pull-down menus providing scriptures, prayers, meditations and biographies of the saints whose feasts are celebrated during these seasons. Note that the feast of St. Nicholas of Myra -- yes, that St. Nicholas -- was back on Dec. 6. Another page suggests family movies for the seasons, some obvious (think "The Nativity Story") and some not so obvious (think "Ernest Saves Christmas").

The Christmas season has always been complicated. Many early Christians celebrated the birthday of Jesus on May 20, while others used dates in April and March. Most early believers, however, emphasized the Jan. 6 feast of the Epiphany.

Then, sometime before 354, Christians in Rome began celebrating the Feast of the Nativity on Dec. 25, which created tension with the Eastern churches that were using different dates. Then, in 567, the Second Council of Tours established Dec. 25 as the nativity date, Jan. 6 as Epiphany and the 12 days in between as the Christmas season -- the liturgical calendar's biggest party.

The problem, of course, is that Advent now clashes with the 30-something or 40-something days of the secular season -- called "The Holidays" -- that begins with the shopping mall rituals of Thanksgiving weekend. For most Americans, Christmas Day is the end of "The Holidays," even though it is the beginning of the real Christmas season.

While many Christians still observe Advent -- especially Anglicans, Lutherans and other mainline Protestants -- some older Roman Catholics may remember when the guidelines for the season were stricter. In Eastern Orthodoxy, the season is still observed by many as "Nativity Lent."

"In a pre-Vatican II context, Advent looked a lot like Lent," noted Father Rick Hilgartner, associate director of the USCCB's Secretariat of Divine Worship. "It was the season you used to prepare for Christmas, the way Lent helps you prepare for Easter."

Today, it's even hard for priests to follow the rhythms of the church's prayers, hymns and rites, he said. Hilgartner said he tries to stay away from Christmas tree lots and shopping malls until at least halfway through Advent. He accepts invitations to some Christmas parties, even though they are held in Advent.

Now that it's finally Christmas, he feels a pang of frustration when he turns on a radio or television and finds that -- after being bombarded with "holiday" stuff for weeks -- the true season is missing in action.

"It would be different, of course, if we all lived in a monastic community and the liturgical calendar totally dominated our lives," said Hilgartner. "Then we could get away with celebrating the true seasons and we wouldn't even whisper the word 'Christmas' until the start of the Christmas Mass. But the church doesn't exist in a vacuum and we can't live in a cultural bubble. ...

"But it's good to try to be reasonable. It's good to slow down and it's good to celebrate Christmas, at least a little, during Christmas. It's good to try."