Session timing requires a timezone and a date
Spot FX is an over-the-counter market rather than one exchange with a single opening auction. Dealer and broker hours differ. Session labels are conventions; do not infer a fixed share of daily volume or a predictable price pattern from the clock alone.
| Reference | How to define it | Important boundary |
|---|---|---|
| Asian range | Choose an explicit start and end in a named timezone. | Different windows produce different highs and lows; low volatility is not guaranteed. |
| London trading | Use Europe/London for the date being analysed. | London’s UTC offset changes with daylight saving; an apparent range break need not reverse. |
| New York overlap | Use America/New_York and Europe/London together. | US and European clock-change dates differ, so the UTC overlap changes during parts of the year. |
| WMR closing benchmark | 4:00 pm London local time on applicable weekdays. | This is not always 16:00 UTC and is not an executable quote for every trader. |