International Workers' Day,well known as May Day,Labor Day or International Day of Demonstrations which is the celebration festival promoted by International Labor Movement and held by workers.

May.3 is National Day in Poland.

May.5 is Childrens’ Day in Japan.

May.9 is Victory Day（День победы）in Russia.

May.14 is Mothers’ Day.

May.18 is Fathers’ Day in Germany.

May.19 is National Father's Day, Youth and Sports Day (Atatürk'ü Anma Gençlik ve Spor Bayramı）in Turkey.

May.20 is National Day in Cameroon.

May.25 is Revolution Memorial Day in Argentina.

May.25 is Independence Day in Jordan.

May.26 is Pentecost in Israel.

May.27 is Childrens’ Day in Nigeria.

May.30 is Memorial Day in USA.