The high season on St. Maarten/St. Martin begins in December and runs through the middle of April. During the off-season, hotel rooms can be had for as little as half the high-season rates. The French side's Carnival is a pre-Lenten bash of costume parades, music competitions, and feasts. On the Dutch side, Carnival takes place after Easter - last two weeks of April - with a parade and music competition. On the French side, parades, ceremonies, and celebrations commemorate Bastille Day on July 14 and there's more revelry later in the month on Grand Case Day. On the Dutch side, early March has the Heineken Regatta, with as many as 300 sailboats competing from around the world. (For the experience of a lifetime, some visitors can purchase a working berth aboard a regatta vessel.)

 
Both sides of the island celebrate specific holidays related to their government and culture, and some, such as New Year's, the Easter holidays (moveable, Apr. or May), Labor Day (May 1), Christmas, and Boxing Day (Dec. 26) are celebrated together.  

Other French-side holidays are Ascension Day (Aug. 15), Bastille Day (July 14), Schoelcher Day (July 21), All Saints' Day (Nov. 1), and the Feast of St. Martin (Nov. 11). Other Dutch-side holidays are Antillean Day (Oct. 21) and St. Maarten Day (Nov. 11; this coincides with Feast of St. Martin on the French side). On many holidays, government offices, shops, and even gas stations may be closed.

Language - The language on the St. Maarten side is officially Dutch, and it's officially French on St. Martin. But most people speak English. A French-based patois is spoken by a small segment of the local populace, as is French Creole, Spanish, and Papiamento.

Tipping - Most hotels on both sides on the island add a 10% or 15% service charge to your bill; make sure you're clear on whether or not it's already included in the original price quoted to you. Most restaurants automatically add a service charge to your bill. If service has not been added (unlikely), it's customary to tip around 15%. Taxi drivers also expect a 15% tip.

Liquor Laws - On both sides of the island, liquor is sold in grocery and liquor stores on any day of the week. It's legal to have an open container in public, though the authorities are very strict about littering, disorderly behavior, and drunk driving.