BDS / Intraday usability
Trading Sessions and Time Zones for Intraday Signal Reviews
Use a named venue session and absolute timestamps. A personal calendar day is not a universal trading day.
Choose the venue, not a generic clock
An intraday mandate needs the instrument, venue and relevant session definition. The NYSE publishes venue-specific trading hours and holiday calendars; other markets and products have their own schedules. Do not apply one equity-session rule to every instrument.
The session boundary can include auctions, early closes and periods outside the core session. Check the official calendar for the actual date and product. A label such as market open cannot establish these details by itself.
Store the instant separately from display
Retain an absolute timestamp with a stated offset or UTC designation, and keep the venue time-zone name beside it. A display clock is a presentation of the instant. Two readers can see different local dates without changing when the object existed.
Avoid a fixed-offset nickname when daylight saving can change the relationship. A named IANA zone can display a known UTC instant consistently. The workbench takes explicitly UTC inputs and converts their display; it does not guess an ambiguous local-time input.
Handle calendar transitions
Different places can change daylight saving on different dates. A routine copied from a previous week may display a different local hour. Check the relevant date rather than assuming that a remembered conversion is permanent.
A conversion does not prove the exchange is open. Holiday and early-close eligibility is a separate calendar check. The tool is not a live market-hours service and does not load a full venue calendar.
Worked display example
Hypothetical session examples use fixed UTC instants and named zones. Changing the display from New York to Paris changes the printed clock, not the delay between publication and receipt. That delay is computed from the same absolute instants.
The reader must still confirm whether the chosen boundary matches the actual venue and date. Do not treat an illustrative session interval as an authoritative schedule for a selected instrument.
Keep cutoff policies visible
Define whether an entry at the stated expiry is allowed and whether the closing boundary is exclusive. A few seconds of boundary ambiguity can change an intraday observation state. The original product rule governs; a worksheet assumption must stay labelled an assumption.
Record messages outside the chosen session as such rather than deleting them. They can be valid source objects but unsuitable for the reader's mandate.
Publish a clock record
Retain venue, calendar source, UTC instants, display zone, cutoff convention and any clock uncertainty. This lets another reader understand the chronology without reproducing a private account.
No measurement of a provider's latency is produced by entering these fields. They organize a hypothetical or reader-supplied timeline, with provenance and limitations remaining separate.
Holiday versus timezone errors
A timezone conversion can be correct while the calendar boundary is wrong for the instrument or date. Keep these as separate checks. The workbench does not implement every holiday, product session or early close. A user-entered interval remains an assumption even when its display in another zone is accurate.
Avoid unlabeled local times
A note such as nine thirty needs a date, zone and provenance. An ambiguous local timestamp can refer to different absolute instants around calendar transitions. This worksheet avoids that inference by taking UTC fields. Source records should retain their actual offset or zone rather than being silently converted from a remembered routine.
Keep uncertainty proportional
If clocks are manually observed or source labels lack seconds, do not present a millisecond delay. Store the precision and uncertainty actually supported. A point calculation is a scenario under entered assumptions; it is not a measurement of the provider's routing chain or the reader's end-to-end action time.
Evidence Packet
| Evidence object | Record to retain |
|---|---|
| Venue clock | Instrument, session and official calendar |
| Absolute time | UTC or explicit offset with provenance |
| Display and cutoff | IANA zone and boundary conventions |
Related Session Questions
Primary References
The sources support documented mechanisms and source definitions. Our procedure and teaching examples are not completed paid-feed, latency or account tests.