Direct answer: hours of the US forex session
There is no single universally fixed number of hours for the “US forex session.” In practice, people usually mean the trading hours around the US (New York) business day, often described as roughly the New York session period (approximately late morning to early evening in US time). However, forex trading is decentralised and liquidity can be present outside that window.
A careful way to answer your question is to state the assumption: if you define the “US forex session” as the New York trading window in US time, then the commonly cited duration is about 6–7 hours. If you include additional liquidity overlap before and after that window (for example, overlap with London), the effective number of hours with active liquidity becomes longer.
Explanation: what “US forex session” usually means
Forex does not trade on one exchange with one clock. Instead, it trades through a global network of participants. As a result, the same term (“US session”) can be defined differently:
- Clock-time definition: The session is mapped onto the New York business day in US time zones. Under this definition, the “US session length” is typically stated as about 6–7 hours.
- Liquidity/participation definition: The session is defined by when market participants are actively active and liquidity is reliably available. Under this definition, the “US-relevant” trading period can extend because the US session overlaps with other regions (especially Europe), and activity can occur before the clock-time window begins.
Because these definitions differ, two sources can both be “correct” while quoting different hour ranges.
Example checks: how to verify the hours you mean
To make your own number independently verifiable, align your definition first:
- Pick a time zone. Decide whether “US time” means New York local time (Eastern Time/ET) and whether you are using a specific date (because daylight saving time can change the relationship to UTC).
- Choose the session boundary rule. For instance: “start at the commonly described New York market open and end at commonly described New York market close,” or instead “measure until liquidity noticeably thins.”
- Compare with overlap. If your goal is “hours during which US overlap occurs,” include the time when US and European activity both contribute. That typically increases the effective duration beyond the basic 6–7 hour clock window.
These checks won’t produce one universal answer, but they do produce a defensible hour range tied to a definition.
Limitations and uncertainty
- No fixed global agreement: “US forex session hours” depends on how someone defines the US session boundary.
- Different data feeds: Liquidity and activity can appear in broker or platform charts at times that do not match a simplified “6–7 hour” description.
- Daylight saving time effects: If you convert “US time” to UTC or other time zones, the duration in another time zone may shift across parts of the year.
- No future guarantees: Even with a clear definition, actual activity intensity can vary day to day.
If you tell me which definition you want (clock-time in New York time, or a liquidity-based “effective hours” view), you can convert that into a specific hour range for your use case without relying on real-time predictions.