These are the Dutch bank holidays. Note that public transport, museums and restaurants run a different schedule on these days, while most shops are closed.
New Year's Day | 1st of January
Good Friday | A Saturday in March or April, preceding the Easter weekend
1st Day Of Easter & 2nd Day Of Easter | A Sunday & Monday in March or April
King's Day | 27th of April
Liberation Day | 5th of May
Ascension Day | On a Thursday, 40 days after Easter Sunday
Pinksteren (Pentecost) | 7 weeks after Easter Sunday
Christmas | 25th & 26th of December