Beijing time: 20 1 1 year: February1-15 Beijing time: 20 12 years: February10-1. In fact, the time should be fixed every year, but because there are college students from all over the world participating in the competition, the time will be changed occasionally because of something. For example, in 20 13, the mathematical modeling competition for American college students was originally scheduled for one day and three nights from Lunar New Year's Day to May 1st in China. After consultation with China, it was changed to around the Lunar New Year in China.