1) April observance 
Koningsdag (Nl-Koningsdag.ogg) or King`s Day is a national holiday in the Kingdom of the Netherlands. Celebrated on 27 April (26 April if the 27th falls on a Sunday), the date marks the birth of King Willem-Alexander. From 1890 to 2013, the day was known as Koninginnedag (Nl-koninginnedag.ogg) or Queen`s Day. The holiday was first observed on 31.....