Puerto Rico operates on Atlantic Standard Time (AST) year-round, which is 4 hours behind Coordinated Universal Time (UTC-4). Puerto Rico does not observe daylight saving time, so the time difference with mainland US cities varies throughout the year.
Puerto Rico is a US territory located in the Caribbean. During Eastern Standard Time (winter), Puerto Rico is 1 hour ahead of New York. During Eastern Daylight Time (summer), Puerto Rico and New York share the same time. San Juan, the capital, is the main business and tourism hub.
Puerto Rico is home to El Yunque, the only tropical rainforest in the US National Forest System. The island's decision not to observe daylight saving time means that for half the year, Puerto Rico is in sync with New York, and for the other half, it's an hour ahead—a quirk that business travelers need to remember.