The Chinese animal signs are a 12-year cycle used for dating the years. They represent a cyclical concept of time, rather than the Western linear concept of time. The Chinese Lunar Calendar is based on the cycles of the moon, and is constructed in a different way than the Western solar calendar. In the Chinese calendar, the beginning of the year falls somewhere between late January and early February. The lunar year has twelve moons and each moon lasts for just over twenty-nine and a half days. In order to make the days in each moon full days, there are six 'small' months which have twenty-nine days each and six larger months which have thirty days each, making a total of 354 days, eleven days short of the solar calendar. Occasionally the length of the Chinese years changes and there may be either seven 'small' months (a total of 353 days), or sometimes seven 'large' months (a total of 355 days). As each year passes, the lunar calendar usually falls short of the solar year by ten to twelve days, so in order to bring the lunar calendar in line with the solar calendar an extra month is added at roughly three-year intervals. The Chinese have adopted the Western calendar since 1911, but the lunar calendar is still used for festive occasions such as the Chinese New Year or when Chinese horoscope is used. Many Chinese calendars will print both the solar dates and the Chinese lunar dates