In the book they do not celebrate Christmas which is the only mentioned holiday, (besides birthdays).
Yes. Nearly every religion has ritual feasts.
Muslims do not celebrate Easter, much like Christians do not celebrate Ramadan. For most Muslims, besides seeing a lot of bunnies and eggs in the store, Easter is just another day. Muslims do believe that Jesus lived, but they do not have the same beliefs about him as Christians. They do not have a crucifixion story as part of their history of his life, so there would be no resurrection to go along with it.
Besides for 2 exceptions, all Jewish holidays were given to Moses by G-d on Mt Sinai more than a millennium before the protagonist of Christmas was born. Jews don't celebrate Christmas because Jesus plays no role in our lives and beliefs. Christmas is a Christian holiday, not a Jewish one. For exactly the same reason that Christians don't celebrate Ramadan, Yom Kippur, or the Chinese New Year: Because the date doesn't mark any occasion or event that has any significance in their history, philosophy, or culture.
The reason why some Christians don't celebrate Christmas is because the bible does not exactly state the date of the birth of Jesus Christ. There is no record that indicates he was born on December 25th. Besides, if Jesus wanted his birthday celebrated, don't you think he would have mentioned it? Or wouldn't there have been records in the bible indicating that his apostles or disciples celebrated it? Christmas was first started as a celebration that fell inline with the Pagan Roman festival of Saturnalia. It was adopted by many unbelievers as the birthday of Jesus, even though the scriptures point to his birthday being some time in the Fall, and was incorporated into Church teachings in an attempt to water down the Pagan history of the celebration. Interestingly, there is no record that Jesus observed or celebrated his own birthday. Since the word "Christian" is defined as "Christ-like" as in imitating Christ, or behaving in the same manner as he, some feel that a true Christian wouldn't celebrate a holiday such as Christmas.
By playing games
Yes
jesuses birthday
The U.S. and Canada celebrate Thanksgiving. Some countries which celebrate a similar holiday include Germany, Japan, and Liberia.
It is more of a philosophy than a religion. Just like buddhism is more of a philosophy than a religion as well.
Besides the United States and Mexico? Sure, anywhere you have a Mexican community, some of them will organize to celebrate the occasion.
Besides this coming Christmas in 2011, the last time Christmas fell on a Sunday was in 2004.