RESEARCHOpen ThesisMemo Start with New York time
The regular US stock session runs from 9:30 a.m. to 4:00 p.m. Eastern Time on normal trading days. Use ET rather than assuming EST applies throughout the year. New York alternates between standard and daylight time. The schedule for an individual broker, instrument or extended-hours venue can differ from the regular stock session.
Convert the date, not just the hour
For readers in mainland China, the normal session is 9:30 p.m. to 4:00 a.m. the following day when New York uses daylight time, and 10:30 p.m. to 5:00 a.m. the following day during standard time. These are time-zone conversions, not a guarantee that the market opens on a particular date. Set a calendar to America/New_York and convert the actual trading date to your local zone.
Check holidays and early closes
Before scheduling a trade, consult the exchange calendar for the relevant year. Do not assume a weekday always contains a full session or that a US holiday matches a local holiday. A hypothetical reminder set for Monday evening could fall on an exchange closure. An early-close session also changes how long an order may have to execute. Keep calendar checks separate from your view on the stock.
Make a pre-trade clock check
Write down the exchange date, local date, selected session and order expiration. Confirm that the quote is current and that your broker supports that session for the security. A displayed price can remain on screen while the regular market is closed. If an order is queued for the next opening, review it again before that session rather than assuming the earlier quote will still be available.
Educational material, not personalized investment advice. Examples are hypothetical. Verify current disclosures and broker rules before acting.