The Christmas tree custom as we know it began in Germany in the 16th century, when pious Christians carried decorated trees into their homes. According to legend, Martin Luther, a 16th-century Protestant reformer, was the first to put lit candles to a tree. Christmas lights were made possible by electricity. Commercial Christmas trees became popular in the 19th century. Today, people of many religions around the world celebrate Christmas. It is a religious holiday for Catholics and Anglicans, but not for Protestants. The date of Christmas varies from year to year because it is calculated from the birth of Jesus Christ. However, most countries adopt a date between December 25 and January 7 to mark the occasion. Christmas trees are used to decorate homes throughout the world during the Christmas season. They don't grow on trees, although that isn't unusual these days. A Christmas tree usually consists of several branches with small, cone-shaped objects attached to them. The number of objects on each branch may vary from three or four feet up to a maximum of eight or nine feet. The objects on the tree represent the saints. Catholic churches use white or silver decorations while Protestant churches tend to go with gold or red ones. No one knows exactly why we dress our trees in Christian symbols, but some say it's to honor the saints or even God himself.