The Christian countdown to Christmas has officially begun.

Rooted in preparations for the pagan Saturnalia or winter solstice festivals, Advent begins on the Sunday that falls on or closest to Nov. 30, the feast day of St. Andrew the Apostle, and ends with the first evening prayer of Christmas.

This weekend marks the third Sunday of Advent, which is Latin for “coming.”

The idea behind the season of expectation is to be prepared for the commemoration of the birth of Christ and to look forward to Christ’s second coming at the end of time.

It originated as a period during which converts prepared themselves for baptism through instruction, prayer, fasting and reflection. The length varied from three days to six weeks or about 40 days – the time that Jesus spent in the wilderness.

Orthodox Christians still observe the longer Lenten season, from Nov. 15 until Christmas, rather than Advent.

The most recognized symbols of Advent, a wreath holding four candles and the calendar, grew out of folk rather than religious traditions.

Deep in the winter, Northern Europeans lit candles on wheel-shaped bundles of evergreen. Both the circular shape and the evergreen symbolized life. Eastern European Christians adopted the tradition and by the 16th century were making Advent wreaths nearly identical to ones used today.

Traditionally, an advent wreath contains four candles – three purple and one rose or pink. Purple dyes were so rare and costly that they were associated with royalty. Blue candles, representing the night sky before daylight returns, are also used.

Candles are lit each Sunday during Advent.

The first, representing hope, is called the Candle of the Prophet and recalls the prophecies foretelling the coming of Christ. The second, symbolizing peace, is the Bethlehem Candle, for the town where Jesus was born.

The third, the rose-colored candle, represents joy and is called the Shepherd Candle in honor of the shepherds to whom the birth was announced. The fourth, symbolizing love, is the Angel Candle in remembrance of the angels who heralded Christ’s birth. A white fifth candle is sometimes lit and placed inside the Advent wreath on Christmas Day.

The architect of Advent as observed by Western Christianity was Pope Gregory I, who fixed the season at four weeks, composed seasonal prayers and antiphons, and arranged the Mass and Office lectionary.

An Advent calendar is a card or poster or computer image with 24 small doors. One is to be opened each day from Dec. 1 through Christmas Eve. Beneath each door is a picture, traditionally images from the Hebrew Bible. Advent calendars first appeared in Germany in the late 1800s and spread through Europe and North America. Many Advent calendars today have no religious content and their doors open to reveal teddy bears, pieces of chocolate and photos of pop stars.

Compiled from a variety of sources, including The Catholic Encyclopedia, www.pulpit.org, www.kencollins.com, www.factmonster.com and the Encyclopedia Britannica.