Complete Guide to US Stock Trading Hours
— DST and a Korean-Time Conversion Table
The US regular session runs 9:30–16:00 Eastern Time (ET) for both the NYSE and Nasdaq. Korean time shifts by 1 hour depending on daylight saving time, and knowing the premarket and after-hours windows too lets you react quickly to news and earnings.
Regular-Session Hours
The NYSE (New York Stock Exchange) and Nasdaq both open at 9:30am and close at 4:00pm, US Eastern Time (ET). That's a total of 6 hours 30 minutes of regular trading, closed on weekends and US holidays.
| Session | US Eastern Time (ET) | Korean Time — DST | Korean Time — Winter |
|---|---|---|---|
| Premarket | 04:00–09:30 | 17:00–22:30 | 18:00–23:30 |
| Regular session | 09:30–16:00 | 22:30–05:00 (next day) | 23:30–06:00 (next day) |
| After-hours | 16:00–20:00 | 05:00–09:00 | 06:00–10:00 |
What Is Daylight Saving Time (DST)?
Every year, the US moves its clocks forward 1 hour on the 2nd Sunday of March, and back 1 hour on the 1st Sunday of November. This is called Daylight Saving Time (DST).
- During DST, US Eastern = EDT (UTC-4) → a 13-hour difference from Korea (KST, UTC+9)
- In winter, US Eastern = EST (UTC-5) → a 14-hour difference from Korea
The key thing to note: Korea does not observe daylight saving time. US market hours shift suddenly at the March and November transition points, so it's worth marking your calendar ahead of time. For the transition rule itself and common mistakes, see the DST transition rules.
Strategy for the First Day of a New Regular Session
If important news broke in the US overnight, a Korean investor is meeting the regular session after the price has already moved significantly in premarket. Check the premarket move first, then watch whether direction stabilizes once the regular session opens. For more detail on premarket and after-hours, see the complete guide to premarket and after-hours.
Holidays and Early Closes
On major US holidays, the entire exchange is closed, and on certain days the exchange designates it closes early at 13:00 ET (2am Korea time during US DST, 3am in winter). The usual early-close days are the day after Thanksgiving (Black Friday) and Christmas Eve; the day before Independence Day also qualifies in some years (2026 has no July early close — July 3 is the observed holiday). It's worth making a habit of checking the NYSE's official holiday calendar before you plan to trade. For the full 2026 list of market holidays and early closes, see the complete guide to US market holidays and early closes.
- New Year's Day (Jan 1), Martin Luther King Jr. Day (3rd Monday of January)
- Presidents' Day (3rd Monday of February), Memorial Day (last Monday of May)
- Independence Day (Jul 4), Labor Day (1st Monday of September)
- Thanksgiving (4th Thursday of November), Christmas (Dec 25)
High-Volatility Windows
US economic data releases usually cluster around 8:30am ET (21:30 Korean DST time). A Fed rate decision is released at 14:00 ET (3am Korean time, DST), and the FOMC chair's press conference follows 30 minutes later at 14:30 ET. The VIX fear index can spike during these windows, and the whole market can get shaky. A sudden sharp drop can even trigger a circuit breaker.
Frequently Asked Questions
What is the US regular-session time in Korean time?
When does daylight saving time start?
What's the difference between premarket and the regular session?
When are US stock market holidays?
Related Reading
- Complete Guide to US Market Holidays and Early Closes
- DST Transition Rules
- Complete Guide to Premarket and After-Hours
- Single-Stock Trading Halts
- Complete Guide to US Stock Splits
- Complete Guide to Reverse Splits
- Complete Guide to the ADR (American Depositary Receipt)
- Complete Guide to T+1 Settlement
- Circuit Breakers and Sidecars, Fully Explained
- Overseas Stock Tax Calculator