It's for a holiday. Not christmas. Not the muslim migration / hajj to Mecca. Not religious for most, it's a family holiday. The most important holiday in China.
It's the Chinese Spring Festival, also known as Chinese New Year. In China, this is the Chūnyùn Travel season. The number of travelers has exceeded 2 billion people. People return to their families, from work or study around the country and abroad, for reunion and to renew ties. As far as I know, there is no stupid culture war or "war on New Year" - they are not that silly.
Here is a map of the largest human migration on earth, via Badu. Badu is the Chinese answer to google. They give a higher number, 3.65 billion trips taken.
Chinese New year, also called Lunar New Year, starts tomorrow. The travel season extends about 40 days. Business Week - travel chaos. I couldn't deal with the crowds. Travel in China, one has to give up ideas of courtesy and personal space, and accept surprising rudeness. But I do like the idea of a massive, family oriented holiday when people get together with the families and clans, and celebrate one another just for being together.
Lunar New Year starts on a different date each year. Each year has a zodiac symbol. 2014 will be the year of the Horse.
The festival did have religious implications, but is now secular. "The entire attention of the household was fixed on the celebration...business life came nearly to a stop...homes were thoroughly cleaned to rid them of "huiqi," or inauspicious breaths, which might have collected during the old year. Cleaning was also meant to appease the gods who would be coming down from heaven to make inspections. Ritual sacrifices of food and paper icons were offered to gods and ancestors. People posted scrolls printed with lucky messages on household gates and set off firecrackers to frighten evil spirits. Elders gave out money to children. In fact, many of the rites carried out during this period were meant to bring good luck to the household and long life to the family–particularly to the parents. Most important was the feasting. On New Year's Eve, the extended family would join around the table for a meal that included as the last course a fish that was symbolic of abundance and therefore not meant to be eaten. In the first five days of the New Year, people ate long noodles to symbolize long life. On the 15th and final day of the New Year, round dumplings shaped like the full moon were shared as a sign of the family unit and of perfection. History.com