Stoker's Day is held on April 15. It is celebrated in spring, at the end of the heating season. All shifts workers gether in the boiler room to extinguish the boilers and begin to celebrate. The date of this celebration is not fixed. The local authorities decide when to start and when to finish the heating season but usually it hapends not later than April 30 if the average air temperature is above +8 for 3 days in a raw. This event in the second decade of the month april is annual.
International Moment of Laughter Day on April 14 (is focuses on laughter as a way to de-stress);
That Sucks Day on April 14 (Throughout the history of the holiday and the organization that sponsored it, That Sucks LLC, they seek to exemplify all that is terrible and wrong in the world);
Rubber Eraser Day on April 15 (Joseph Priestley discovered the eraser in 1770, using pieces of rubber imported from Brazil. Then in 1858, Hyman Lipman of Philadelphia, Pa., patented the pencil with an eraser at the end);
Foursquare Day on April 16 (4sqDay or Foursquare Day was coined by Nate Bonilla-Warford, an optometrist from Tampa, Florida on March 12, 2010 being the 4th month and the 16th being equal to four squared. The idea came to him while "thinking about new ways to promote his business". FitBy4sqDay has been a quest by foursquare users to reach new fitness goals and live in a healthier way and is an excellent opportunity for local businesses to shine);