January 1 (New Year's Day / Nieuwjaarsdag)

New Year's Day is an important holiday in Holland. Banks and offices are closed. Many attractions are also closed (see Closed on New Year's Day and Open on New Year's Day).
Many shops are closed, but not all of them, particulary in the centre of Amsterdam.

Good Friday / Goede Vrijdag
The Friday before Easter. Banks and government offices are closed, but attractions and shops are open.

Easter / Pasen
In the Netherlands, Easter has consists of 2 official holiday: First and Second Easterday. The First Easter Day is always on a Sunday, the Second on a Monday.
On First Easter Day attractions are normally open. Shops can be closed, but not all of them. Many supermarkets are open. On Second Easter Day, banks and government offices are closed, but everything else is open.
During the Easter weekend, accommodation may be more difficult to find.

King's Day / Koningsdag
This is the birthday of King Willem Alexander, April 27. If April 27 is on a Sunday, King's Day is on Saturday April 26.
Everyone in the Netherlands is free to sell things outside on the street. Amsterdam is famous for its enormous party on this day, attracting up to half a million visitors. The entire city centre is full of people, especially the old centre and the Jordaan area.
Dance parties tend to be organized out of the centre, in order to alleviate the burden for the centre of Amsterdam.
The theme colour is orange, because of the Royal House is also called the House of Orange.
Shops and many attractions are closed (see Open on King's Day and Closed on King's Day for attractions that are closed or open on Kings' Day.

Labour Day / Dag van de Arbeid
May 1 is not an official holiday in Holland.

Pentecost / Pinksteren
Like Easter, this consists of 2 consecutive holidays, 1e and 2e Pentecost day, on Sunday and Monday.
This holiday is not a big thing in the Netherlands. Shops and attractions are open as usual (but banks and government offices are closed)

Christmas / Kerst
Christmas also has 2 official holidays, December 25 and December 26. On Christmas Day itself (December 25), many attractions, shops, restaurants are closed, and so are banks and government offices (see Closed on Christmas Day and Open on Christmas Day for attractions that are open/closed on December 25).

Some supermarkets in Amsterdam are open throughout the holidays, especially in the centre of town.

New Year's Eve / Oudejaarsdag
December 31 is not an official holiday, so shops and offices are open. Attractions may have different opening hours (they often close earlier than normal).
On December 31, between 8pm and midnight, there is no public transport. There are also no trains!