Subtle & customizable audible cues to indicate when charts turnover, plus world clocks for any market — by & for professional traders
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Subtle & customizable audible cues to indicate when charts turnover, plus world clocks for any market — by & for professional traders
Open the appGuidance last reviewed 2026-08-18
The hours when London and New York are both open carry a large share of the day's activity. Most traders learn roughly where that window sits and stop thinking about it — which works for most of the year and quietly stops working for about four weeks of it.
The overlap runs 8:00 AM to 12:00 PM New York time — except for roughly four weeks each year, when it shifts an hour because the US and Europe change their clocks on different dates.
| London time | New York time | UTC | |
|---|---|---|---|
| London session | 08:00 – 17:00 | 03:00 – 12:00 | 08:00 – 17:00 |
| New York session | 13:00 – 22:00 | 08:00 – 17:00 | 13:00 – 22:00 |
| Both open | 13:00 – 17:00 | 08:00 – 12:00 | 13:00 – 17:00 |
Those are the standard-time figures, with London five hours ahead of New York.
Liquidity. London is the largest FX center in the world, handling a substantial share of global turnover on its own. For four hours a day the largest center and the second largest are open together, and the window is commonly described as carrying more than half the day's FX volume.
Spreads. More participants generally means tighter quotes on the major pairs. The same instrument can cost noticeably more to trade in the thin hours.
And the data lands inside it. Most major US releases — CPI, PPI, the employment report — come out at 8:30 AM New York time, which sits half an hour into the overlap. That is not a coincidence anyone planned; it is why the window has a reputation for decisive moves rather than merely busy ones.
The United States and Europe change their clocks on different dates, and have done since 2007.
| Clocks go forward | Clocks go back | |
|---|---|---|
| United States | Second Sunday in March | First Sunday in November |
| European Union / UK | Last Sunday in March | Last Sunday in October |
Those rules do not line up, so twice a year there is a gap where one side has moved and the other has not.
| Year | US forward | EU forward | Mismatch | EU back | US back | Mismatch |
|---|---|---|---|---|---|---|
| 2026 | 8 Mar | 29 Mar | 3 weeks | 25 Oct | 1 Nov | 1 week |
| 2027 | 14 Mar | 28 Mar | 2 weeks | 31 Oct | 7 Nov | 1 week |
| 2028 | 12 Mar | 26 Mar | 2 weeks | 29 Oct | 5 Nov | 1 week |
The spring gap is the long one, and it varies — three weeks in 2026, two in 2027 and 2028 — because the US date moves around within March while the European one is pinned to the last Sunday.
Nothing about either exchange's own hours. London still opens at 08:00 in London. New York still opens at 09:30 in New York. What changes is the distance between the two clocks.
| Normally | During the mismatch | |
|---|---|---|
| London ahead of New York by | 5 hours | 4 hours |
| Overlap, in UTC | 13:00 – 17:00 | 12:00 – 16:00 |
| US 8:30 AM data, in UTC | 13:30 | 12:30 |
| US 8:30 AM data, London time | 13:30 | 12:30 |
So for someone in London watching US data, the release arrives an hour earlier than usual for two or three weeks — and then goes back. For someone in New York watching the London close, it happens an hour earlier too.
If you have memorised any London time as an offset from your own clock, it is wrong during these weeks. Not approximately — exactly one hour wrong.
Japan does not observe daylight saving at all. Tokyo stays on the same offset every day of the year. Every change in the gap between Tokyo and London, or Tokyo and New York, is caused entirely by the other side moving. Nothing happens in Japan and the relationship changes anyway — four times a year.
Australia runs the opposite way. Its seasons are reversed, so Sydney goes onto daylight saving in October and comes off it in April — moving in the opposite direction to the northern hemisphere on dates that match neither the US nor the EU.
Add it up and someone in Europe or the US watching the Asia-Pacific open has more transitions to track than the two they know about, several of which are invisible from where they are sitting.
The habit that avoids most of the trouble is to stop converting in your head.
A clock showing several cities at once, each in its own local time, sidesteps the arithmetic — it reports what each city's clock says rather than working from a remembered offset. When one region moves and the other has not yet, the displayed times change with it and the new overlap is there to be read rather than calculated.
That is the argument for a multi-timezone market clock in general — and it is worth most in exactly the weeks when people are most likely to be an hour out.
| Term | Meaning |
|---|---|
| Session | The hours a given financial center is actively trading |
| Overlap | A period when two centers are open simultaneously |
| UTC / GMT | The reference timezone. UTC does not observe daylight saving, which is why schedules are often published in it |
| DST | Daylight saving time — clocks moved forward in spring, back in autumn |
| Offset | How far a timezone sits from UTC. This is what changes when the clocks move, not the local opening time |
Chart Ding is a market clock with customizable alarms for traders — candle-close alerts, world market sessions, and holiday warnings. Open the app.
Nothing on this website is trading or investment advice. Chart Ding is a market clock and alarm tool — it does not recommend trades, evaluate strategies, or take account of anyone's circumstances. Nothing here should be construed as a recommendation or relied on as the basis for a trading decision. Consult a licensed professional before placing real money at risk. Trading involves risk of loss.