MarketFrame

Blog / When does the US stock market open in UK time? Why the answer changes twice a year

When does the US stock market open in UK time? Why the answer changes twice a year

The NYSE and Nasdaq regular session runs 9.30am to 4pm Eastern Time, which is 2.30pm to 9pm UK time for most of the year. For a short spell each spring and autumn the US and UK clocks change on different dates, and the US session starts and ends an hour earlier on the UK clock.

By MarketFrame · Published 13 October 2026

The condition that changes the answer: in a mismatch spell the US session runs 1.30pm to 8pm UK time. London's own hours do not move, because they are set in UK time.

The short answer: US and London hours in UK time

These are the published hours:

In UK time, the US session runs 2.30pm to 9pm in a normal week and 1.30pm to 8pm in a mismatch week. We worked out those UK times from the Eastern times. Neither US exchange quotes them.

London's session also has auctions around it. Orders are gathered for a short period and matched at a single price, with one at the open and one at the close. The exact auction windows are in the exchange's trading parameters document, which is linked from its business days page. Check them there rather than copying a figure from somewhere else.

Why 2.30pm is not always 2.30pm

US hours are fixed in Eastern Time. Both countries put their clocks forward an hour for summer, so for most of the year they stay five hours apart, and 9.30am in New York is 2.30pm in London.

The two countries change their clocks on different Sundays, though. According to gov.uk, UK clocks go forward one hour at 1am on the last Sunday in March and back one hour at 2am on the last Sunday in October. The US uses its own dates. Between the two changes the gap is four hours, so the US open lands at 1.30pm UK time and the close at 8pm.

This happens once in spring and once in autumn. For a UK reader the effect is the same each time: during the spell, the whole US session starts and ends an hour earlier on the UK clock.

Autumn 2026: when the mismatch starts

UK clocks go back on Sunday 25 October 2026 (gov.uk). From Monday 26 October the UK is on Greenwich Mean Time, while the US clocks have not yet gone back. So from 26 October:

The spell ends when US clocks go back, on a later Sunday. From the next trading day, the usual 2.30pm to 9pm pattern returns. We have not printed the US date because none of the primary sources we checked state it. Look it up before you rely on it.

The spring spell works the same way. UK clocks next go forward on Sunday 28 March 2027 (gov.uk), and the US changes on a different Sunday close to it.

The overlap window and why it matters when reading news

London closes at 4.30pm. So both markets are open from 2.30pm to 4.30pm UK time in a normal week, and from 1.30pm to 4.30pm in a mismatch week (both calculated).

When a story lands inside that window, both markets meet it at once. When it lands outside the window, only one market is open, or neither. Knowing which one tells you where the first reaction could happen. It tells you nothing about which way it goes.

Pre-market, after-hours and the London auctions: what the extra sessions are

The regular session is not the whole trading day. Nasdaq lists pre-market trading from 4am to 9.30am and after-hours trading from 4pm to 8pm Eastern Time. In a normal week that is 9am to 2.30pm and 9pm to 1am UK time (calculated). The NYSE hours page also lists early and late sessions for some of its markets.

Nasdaq's own page says fewer people trade in these sessions and there is less liquidity. So a move outside regular hours happened on thinner trading than the main session.

In London, the extra sessions to know are the opening and closing auctions described above. On the exchange's half days, the closing process starts from 12.30pm UK time.

Bank holidays and early closes: where to check the calendar

The two calendars do not line up, and the end of 2026 shows how. From the NYSE, Nasdaq and London Stock Exchange calendars:

For any other date, check the London Stock Exchange business days page and the NYSE holidays and trading hours page.

How to read the timing of a story against the session it landed in

Most headlines show a publication time. Some publishers give it in their own time zone, so convert it to UK time first. Then put the story in one of five slots:

  1. Before the London open (before 8am): nothing is trading in London. The first London reaction can only come at the open.
  2. London only (8am to the US open): London is trading and New York has not started.
  3. The overlap (US open to 4.30pm): both markets are open.
  4. After the London close, US still open (4.30pm to 9pm, or 8pm in a mismatch week): the earliest London reaction is the next trading day.
  5. After both have closed: only extended sessions are running, on thinner trading.

This matters for UK-listed companies especially. A story about a FTSE 100 company that breaks at 6pm cannot show up in London trading until the next morning. That is worth knowing before you read too much into the next day's coverage. The guide to the FTSE 100 index explains how the index and its companies fit together.

MarketFrame's daily pages are built around the same timing. Each morning it reads the UK business news from the previous 24 hours on every FTSE 100 company and publishes the result at about 7.45am UK time, before London opens. So one day's page gathers stories from all five slots. Each company gets a tone score from minus 10 (clearly bad news for it) to plus 10 (clearly good). You can see the latest day on FTSE news, past days in the daily overviews, and a sector's history, such as banks. The archive starts on 30 September 2026.

To be plain about it: news tone is not a share-price forecast. A tone score describes what the coverage said. This post makes no predictions, gives no live prices or levels, and gives no advice.

A calm routine: using the timing, not chasing it

It takes about a minute:

  1. Check the date. If it falls between the UK and US clock changes, the US session is an hour earlier on your clock.
  2. Check both calendars for holidays and early closes that day.
  3. Convert the story's timestamp to UK time.
  4. Put it in a slot and note which market, if any, was open.
  5. Read what it actually says, and go to the company's own announcement if there is one.

This routine stops the most common timing mistake: assuming the US is open when it is not, or that it opened at 2.30pm when it opened at 1.30pm.

Questions people ask

What time does the US stock market open in UK time?

The NYSE and Nasdaq regular session opens at 9.30am Eastern Time. That is 2.30pm UK time for most of the year, and 1.30pm in the short spells when US and UK clocks change on different dates. Both UK times are calculated from the Eastern times the exchanges publish.

What time does the London Stock Exchange open and close?

The London Stock Exchange gives its trading hours as 8am to 4.30pm UK time. Auctions sit around that session, and on its half days the closing process starts from 12.30pm. Exact auction windows are in the exchange's trading parameters document, linked from its business days page.

Why does the US open at a different UK time in some weeks?

Both countries move their clocks by an hour, but on different Sundays. Most of the year they are five hours apart. Between the two changes the gap is four hours, so the US session runs 1.30pm to 8pm UK time.

Is the US market open on UK bank holidays, and the reverse?

Sometimes, because the calendars differ. For example, London is closed on Monday 28 December 2026 but that day is not on the NYSE holiday list, and the US is closed for Thanksgiving on Thursday 26 November 2026 while London trades. Check both exchanges' calendars for a specific date.

Are pre-market and after-hours the same as regular trading hours?

No. Nasdaq lists pre-market trading from 4am to 9.30am and after-hours trading from 4pm to 8pm Eastern Time, separate from the 9.30am to 4pm regular session. Nasdaq notes that fewer people trade in these sessions.

Sources