Saint Martin is a 90-square-kilometer island in the northeastern Caribbean divided between France (the northern Saint-Martin) and the Netherlands (the southern Sint Maarten). The French side observes UTC-4, Atlantic Standard Time, year-round. The Dutch side observes the same. The IANA identifier for the French side is America/Marigot.

The border between the two sides has no formal controls. You can drive across it without stopping. Both sides use Atlantic Standard Time, so crossing the border does not change your clock.

This is one of the more pragmatic timezone arrangements in the Caribbean.

The Treaty of Concordia

The island was divided between France and the Netherlands in 1648 by the Treaty of Concordia, one of the older bilateral agreements still in effect. Legend holds that a Frenchman and a Dutchman settled the division by walking in opposite directions from a central point, each claiming the land behind them. The Frenchman walked farther, legend says, because he was drinking wine and the Dutchman was drinking gin; the French side ended up slightly larger.

The actual division was more prosaic: negotiation between colonial powers with competing interests. The French side got 53 square kilometers, the Dutch side 37. Both sides have been happily (and sometimes contentiously) sharing the island for nearly four centuries.

One island, two economies

The French side falls under EU customs rules and uses the euro. The Dutch side uses the Dutch Caribbean guilder and has different tax structures. The result is that shopping patterns sometimes cross the border: certain goods are cheaper on one side, certain services on the other.

The island has been a major tourism destination since the 1970s, known for its beaches, its duty-free shopping, and its gambling (legal on the Dutch side). Hurricane Irma in 2017 caused severe damage to both sides of the island.

For developers

Sources