You can't make an omelette without breaking eggs. (English proverb). We do not inherit the world from our ancestors; we borrow it from our children..
International Sister Cities Day 2017 is on Sunday, March 26, 2017: When exactly is sweetest day? Sunday, March 26, 2017 is International Sister Cities Day 2017. Sweetest Day is an observance celebrated primarily in the Great Lakes region and parts of the Northeast United States on the third Saturday in October[1].
Not to be confused with World Day of Peace. The International Day of Peace, sometimes unofficially known as World Peace Day, is observed annually on 21 September. It is dedicated to world peace, and specifically the absence of war and violence, such as might be occasioned by a temporary ceasefire in a combat zone for humanitarian aid access. The day was first celebrated in 1982, and is kept by many nations, political groups, military groups, and people.