When the market is open

The regular session

The two big US stock exchanges, the New York Stock Exchange and Nasdaq, keep the same hours. Their regular trading session runs from 9:30 to 16:00 New York time, Monday to Friday.

New York time is usually written ET, for “Eastern Time”. Almost every price you see quoted for a US share — the day’s open, its close, its high and low — comes from these six and a half hours.

The market is closed on Saturdays and Sundays, and on about ten holidays a year, such as New Year’s Day, Thanksgiving and Christmas. On a few days around holidays, it closes early, at 13:00 ET. The exchanges publish their holiday calendar in advance, and so does your broker.

The same hours in Baku

Baku is on UTC+4 all year: Azerbaijan does not move its clocks. New York does. It is on winter time, UTC−5 (written EST), for part of the year, and on summer time, UTC−4 (EDT), for the rest. In the US, summer time starts on the second Sunday of March and ends on the first Sunday of November.

So the gap between Baku and New York is 8 hours in summer and 9 hours in winter, and the market opens at a different Baku time in each.

	New York (ET)	Baku, US summer time	Baku, US winter time
Regular session opens	9:30	17:30	18:30
Regular session closes	16:00	00:00	01:00
Early close (some holidays)	13:00	21:00	22:00

In 2026, US summer time ends on Sunday 1 November. From Monday 2 November the session runs 18:30–01:00 in Baku, until US summer time returns on 14 March 2027.

Before the open and after the close

Trading does not stop completely outside the regular session. Many brokers let you trade in two extra windows:

• Pre-market — before 9:30 ET, from about 4:00 at many brokers, later at others. In Baku that is from about 12:00 in summer, or 13:00 in winter.
• After-hours — after 16:00 ET, often until about 20:00. In Baku that runs until about 04:00 in summer, or 05:00 in winter.

The exact hours, and whether you can trade in them at all, depend on your broker.

These windows matter because a lot of news arrives then. Companies usually publish their quarterly results just before the open or just after the close, so the biggest reaction to the news often happens outside regular hours.

Why extra hours are different

Far fewer people trade before the open and after the close. That changes how trading works:

• Wider spreads. With fewer orders waiting, the gap between the best buyer’s and the best seller’s price — the spread — is usually wider.
• Bigger jumps. Lower liquidity means one order can move the price further, so prices can be more jumpy than during the day — higher volatility.
• The price may not hold. A price set by a few trades at 7:00 ET can look very different once the full market opens at 9:30.

The open and the gap

The price at 16:00 is the day’s official close. The next day’s first price — the open — is often different, because news and orders have built up overnight. When the open is well above or below the previous close, people call it a gap. On a chart it shows as a jump between one day’s bar and the next.

In short

The US regular session runs 9:30–16:00 New York time on weekdays, except holidays. In Baku that is 17:30–00:00 during US summer time and 18:30–01:00 in winter, because New York moves its clocks and Baku does not. Pre-market and after-hours trading exist, but with thinner trading, wider spreads and bigger jumps.