Why Reliable Trading Hours Data is Essential

Sell a stock on the NYSE on a Monday, and the cash usually hits your account on Tuesday.

Except when it does not.

Take Columbus Day: U.S. markets are open, but the Federal Reserve is closed. Trades clear a day late. Funds sit idle. Interest is lost. For large firms, that seemingly minor delay can mean millions in opportunity cost or unexpected liquidity crunches.

And that is just one example. Irregularities in global financial calendars create a hidden layer of operational risk that many systems are not built to handle.

Unexpected market closures happen more often than you might think. Recently, typhoons have shut down Hong Kong markets, a computer glitch delayed Japan's opening bell, and the war in Ukraine temporarily closed markets (though they've since reopened). When a national leader dies, markets often close for a day. The NYSE, for instance, closed for former President Jimmy Carter's funeral.

Even sports can have an impact. When Saudi Arabia upset Argentina in the 2022 World Cup, Saudi Arabia declared a national holiday to celebrate, closing markets for the day.

Religious and cultural practices add to the complexity. Islamic holidays are based on visibility of the Moon, so the exact date might not be known until the night before. Trading between different regions also introduces challenges:

• Time zones: Daylight Saving Time starts and ends on different dates in the U.S. and the UK, resulting in four annual time changes to keep track of.
• Regional differences: Some South American markets adjust summer schedules to align with U.S. markets during Daylight Saving Time.

Each country has its own way of observing holidays. If a holiday falls on a weekend, it might be observed the preceding Friday, the following Monday, or not at all. Weekends themselves are not universal—markets in Tel Aviv, for instance, operate Sunday to Thursday.

With so much variation, managing market hours and holidays is harder than it looks. That is why we built TradingHours.com — a reliable source of accurate, up-to-date calendar data for financial applications.

Our Market Holidays & Trading Hours API delivers machine-readable schedules for over 1,100 markets across 106 countries (see our coverage). No more manual updates. No more missed closures.

We handle the complexity — so you can focus on your core business.