Everyday we face numbers in the calendar. The SEOUL ICM 2014 organizing committee made a mathematical calendar using math formulas and facts that are associated with each day of the calendar. The calendar contains various contents from simple contents for elementary school level up to challenging ones that only mathematicians can understand, from common arithmetic operations up to remarkable expressions, and from marvelous jokes up to serious mathematical facts. The main schedule of SEOUL ICM2014 is also included for convenience. Please enjoy the "SEOUL ICM2014 mathematical calendar."