The foreign exchange market operates 24 hours a day, five days a week, across four major trading sessions: Sydney, Tokyo, London, and New York. However, Daylight Savings Time (DST) shifts the absolute clock times of these sessions, creating confusion for traders, affecting liquidity, and altering trading strategies. This guide examines the meaning of forex market hours during DST, practical use cases, how to evaluate session timing, and the risks associated with time changes—so you can trade confidently all year round.
The forex market is decentralized and operates 24 hours a day from Sunday at 5:00 PM ET (10:00 PM GMT) to Friday at 5:00 PM ET (10:00 PM GMT). Trading activity is driven by four major financial centers:
The Bank for International Settlements (BIS) reported in its 2025 Triennial Central Bank Survey that the global foreign exchange market averaged $9.6 trillion in daily turnover. While this immense liquidity makes the market attractive to participants, the Commodity Futures Trading Commission (CFTC) has repeatedly cautioned that retail forex trading is highly speculative and carries significant risk, particularly for those who do not understand the timing and structure of market sessions.
Daylight Savings Time is the practice of moving clocks forward by one hour during the summer months to extend evening daylight. Countries observe DST on different dates:
Because different countries change their clocks at different times, there are periods during the spring and autumn where the absolute UTC times of session opens shift while others remain unchanged. This creates a temporary misalignment in the normal trading calendar.
For example, during the London-New York overlap, when the US is on DST but the UK is not (or vice versa), the overlap window shifts by one hour relative to UTC. This can affect traders who rely on specific times for news releases, order execution, or automated strategies.
The table below shows the standard session opening and closing times in both GMT (winter) and BST (summer), reflecting how DST shifts the absolute times.
| Session | City | Winter (GMT) Open | Winter (GMT) Close | Summer (BST) Open | Summer (BST) Close |
|---|---|---|---|---|---|
| Sydney | Sydney | 22:00 | 07:00 | 21:00 | 06:00 |
| Tokyo | Tokyo | 00:00 | 09:00 | 00:00 | 09:00 |
| London | London | 08:00 | 16:00 | 07:00 | 15:00 |
| New York | New York | 13:00 | 22:00 | 12:00 | 21:00 |
| London-New York Overlap | — | 13:00 – 16:00 | 12:00 – 15:00 |
Times are in GMT (winter) and BST (summer). Note that Japan does not observe DST, so Tokyo times remain constant relative to UTC.
The London-New York overlap is the most active period, accounting for the majority of daily trading volume. During DST transitions, this overlap shifts by one hour, which can impact the timing of volatility spikes and the effectiveness of strategies that rely on specific time windows.
Understanding DST shifts is critical for several types of forex market participants:
A scalper trades the London-New York overlap because of its tight spreads and high volatility. When the UK moves to DST one week before the US, the overlap effectively shifts by an hour, altering the window of opportunity. Scalpers must adjust their trading schedules and ensure their algorithms or manual routines reflect the new timing.
Economic data releases from the US (Non-Farm Payrolls, CPI, Fed announcements) occur at fixed local times. When the US enters DST, these releases shift by one hour relative to GMT. A news trader in London or Tokyo must update their calendar to avoid missing critical announcements.
An automated system programmed to execute trades during specific UTC windows may misfire if it does not account for DST changes. This can lead to unexpected execution during quieter sessions with wider spreads, increasing transaction costs and slippage.
To evaluate and manage the impact of DST on your trading, consider the following criteria:
Maintain a calendar of DST transition dates for all major financial centers. The CFTC and NFA both emphasize that retail traders should be aware of the timing of market sessions and economic releases. The Federal Reserve publishes its meeting and data release schedules in local time, so cross-referencing with your own timezone is essential.
Most trading platforms (MT4, MT5, cTrader) allow you to set the server time or your local time. Ensure your platform is synchronized with your broker's server time, as orders are timestamped and executed based on that reference. During DST transitions, brokers may or may not adjust their server clocks, so you should confirm their policy.
If your strategy relies on specific session times (e.g., the London open, the New York afternoon), review its performance during DST transition periods. The BIS notes that trading volumes can dip during the transition weeks, so you may need to adjust position sizes or trade only during confirmed high-liquidity windows.
For algorithmic traders, audit your code for any hard-coded time references. Use timezone libraries that can automatically detect DST changes, or program your system to use UTC as a baseline and apply the correct offsets based on session location.
Cross-check the times of major economic releases on at least two independent economic calendars. Some calendars automatically adjust for your local timezone, while others display release times in a fixed timezone (usually GMT or ET). Always verify the actual release time in your local time.
The following table summarizes how DST transitions affect the timing, liquidity, and spread characteristics of the four major sessions.
| Session | Standard (Winter) UTC Open | DST (Summer) UTC Open | Liquidity Impact | Spread Impact |
|---|---|---|---|---|
| Sydney | 22:00 | 21:00 | Moderate (AUD/NZD pairs) | Wider during DST transition |
| Tokyo | 00:00 | 00:00 (no DST) | Stable (JPY pairs) | Stable |
| London | 08:00 | 07:00 | High (EUR/GBP pairs) | May widen during transition |
| New York | 13:00 | 12:00 | High (USD pairs) | May widen during transition |
| London-New York Overlap | 13:00–16:00 | 12:00–15:00 | Very High (most liquid) | Tightest spreads |
Tokyo does not observe DST, so its UTC open remains constant year-round. Other sessions shift by one hour during their respective DST periods.
Use this checklist before and during each DST transition to stay prepared:
The US and UK change on different dates, and Australia follows a completely different schedule. Assuming all sessions shift in sync is a major error that leads to missed trades and poor execution timing.
Many brokers do not adjust their server time for DST, or they adjust at a different date than your local timezone. Failing to check your broker's server time can result in orders being executed at unexpected UTC times.
Automated systems that rely on fixed times (e.g., "execute at 14:00 server time") may behave unpredictably if the server time shifts. Always test your EAs on demo during the transition week.
During the week when the US is on DST but the UK is not (or vice versa), the London-New York overlap shifts by one hour. Some traders continue to trade the same UTC window, only to find spreads wider and liquidity thinner. The NFA notes that reduced liquidity can amplify slippage and execution risk.
US data releases (like NFP) shift by one hour relative to GMT when the US enters or exits DST. Traders who do not update their calendars risk missing important releases or trading before the actual data is published.
Forex trading is highly speculative and carries a high level of risk. The use of leverage can magnify both gains and losses. DST transitions introduce additional market risks, including:
The Commodity Futures Trading Commission (CFTC) and the National Futures Association (NFA) both warn that retail off-exchange forex trading is "at best extremely risky, and at worst, outright fraud." The BIS data shows that while the forex market is vast, retail traders represent a very small fraction of total volume and are often exposed to the highest costs.
This guide is for educational purposes only and does not constitute financial, legal, or tax advice. You are solely responsible for your trading decisions. Before trading, understand all risks, verify your broker's regulatory status with the appropriate authority, and never risk more than you can afford to lose.
If you suspect fraud or have been targeted by a scam, report it to the CFTC (866-366-2382) or file a tip at cftc.gov/ConsumerProtection. In the UK, contact the FCA.