The Queen's birthday, in the Netherlands, is a national holiday marked by all kinds of celebrations throughout the country including street parties and other festivities. So if you're going to be vacationing in the Netherlands and can plan your week trip to fall over April 30 (the current official celebration), you'll be able to enjoy this exciting tradition.
Although the current Queen, Beatrix, actually has a birthday some other time during the year, she announced on the day of her investiture that she wanted to continue celebrating her birthday on April 30th, since that was the day of her mother's birthday. The Queen and her family members will visit one or two places in the country that are celebrating each year and have the visits broadcasted on TV.
The original Queen's Day (then Princess Day) was invented in hope that the symbol would foster national unity. That birthday was of Princess Wilhelmina, and it was on August 31. It became the queen's birthday when Wilhelmina became queen after the death of King William III. The day did indeed begin to gain popularity among Dutch school children and then really got the public's attention when the Queen was seriously ill and recovered. When her daughter, Juliana, became queen, the day was celebrated with a parade on April 30. Eventually, the celebrations became so big that custom awarded everyone the day off work and school, and it became an official public holiday.
In honor of the day and national pride, everyone wears orange, the color of the royal family's name - The Family Nassau, House of Orange. If you happen to be visiting the Netherlands over April 30 and will be able to attend the festivals in your area, be sure to wear something orange, and don't forget to look for the Queen!