™An unfilled day order normally expires at the end of its designated trading session; confirm whether the broker includes extended hours.
Orders & Market Structure
Day order
An order that expires if it is not executed by the end of that trading session.
Plain-English context
Put the definition to work.
Confirm which session the order covers; a regular-session day instruction may not remain active in extended hours.
Further reading and verification. Examples are hypothetical, not current quotes or recommendations. Product terms, tax treatment and market rules can change. FINRA — order types and execution