Ratcatcher’s Day, Rat-catcher’s Day or Rat Catcher’s Day is celebrated on June 26 or July 22, commemorating the myth of the Pied Piper of Hamelin. The town of Hamelin in Germany uses the June date. The confusion of dates is because the Brothers Grimm cite June 26 1284 as the date the Pied Piper led the children out of the town, while the poem by Robert Browning gives it as July 22, 1376. It is a holiday remembering rat-catchers, similar to Secretary’s Day.
The Pied Piper of Hamelin (German: Rattenfänger von Hameln, the Rat-Catcher of Hamelin) is the subject of a legend concerning the departure or death of a great number of children from the town of Hamelin (Hameln), Lower Saxony, Germany, in the Middle Ages. The earliest references describe a piper, dressed in multicolored clothing, leading the children away from the town never to return. In the 16th century the story was expanded into a full narrative, in which the piper is a rat-catcher hired by the town to lure rats away with his magic pipe. When the citizenry refuses to pay for this service, he retaliates by turning his power that he put in his instrument on their children, leading them away as he had the rats. – Wikipedia