There's more than a few crazy toasts to King Willem-Alexander in late April, when all of Amsterdam gets drunk in the streets on Koningsdag.
The royal celebrations were first held on August 31, 1885 to honour of the birth of Queen Wilhelmina. After Wilhelmina’s daughter, Juliana, succeeded to the throne in 1949, the day was changed to April 30, the new Queen's birthday. Former Queen Beatrice bought into the fun by celebrating her entry into the world on what was her mother Juliana's birthday, even though her real birthday is in January—not a good month for a street party in Holland.
After his inauguration in 2013, when his mother stepped down, the holiday was changed from Koninginnedag (Queen's Day) to Koningsday (King's Day). It takes place on April 27, the king's real birthday, unless that falls on a Sunday, when it moves to April 26. Holland celebrated Koningsdag for the first time in 2014.