Half-Day Sessions: How to Practice When the Market Closes at 1:00 p.m.
Most trading days run 9:30 a.m. to 4:00 p.m. ET, but a few don't: the day after Thanksgiving and Christmas Eve, the US market only opens for half a day and closes at 1:00 p.m. That leaves 0DTE with a 3.5-hour window, and the 3:30 p.m. cutoff and 3:55 p.m. reminder — both set for a 4:00 p.m. close — never arrive. Before you practice, move your own deadline to 1:00 p.m.
Only two half days are left in 2026
Friday, November 27, the day after Thanksgiving (Black Friday); Thursday, December 24, Christmas Eve. Those are the only two early closes in 2026.
Thursday, November 26 (Thanksgiving) and Friday, December 25 (Christmas Day) are full closures, not half days — no trading and no fresh quotes on those days.
Friday, July 3 is Independence Day (observed), a full closure, and Thursday, July 2 trades normal hours until 4:00 p.m. — not a half day, so don't go by other years' habits.
Dates follow the NYSE calendar; the exchange can change them at short notice, so check before you practice.
The half-day clock: same open, close 3 hours early
The 9:30 a.m. open is unchanged; stocks close at 1:00 p.m.; SPX options trade 15 minutes longer, until 1:15 p.m.
Both half days fall in winter time (13 hours ahead of Beijing): the 9:30 a.m. open is 10:30 p.m. Beijing time the same evening, the 1:00 p.m. stock close is 2:00 a.m. the next morning, and the 1:15 p.m. options close is 2:15 a.m.
The whole session, 9:30 a.m. to 1:00 p.m., is only 3.5 hours — 3 hours shorter than usual, and the window for time decay to work is 3.5 hours too.
Half days are often quieter than usual and spreads can widen — check the spread as a share of the premium before you open anything.
What changes for 0DTE that day
Contracts expiring that day still expire, and the settlement rules don't change (see the settlement-value guide) — a half day doesn't change settlement.
The 3:30 p.m. no-new-open cutoff and the 3:55 p.m. close-out reminder are set for a 4:00 p.m. close, and the market is already shut at 1:15 p.m. — waiting for the 3:55 p.m. reminder means waiting for a reminder that never comes.
After 1:15 p.m. quotes stop updating, so the ET time on the page freezes near 1:15 p.m. and the data goes stale — that is normal, not a data outage.
With only 3.5 hours, direction alone isn't enough — you also have to be fast and far enough: if the index hasn't reached breakeven by the close, a long option's premium still goes to zero.
How to practice a half day in the simulator
Write your exit plan's time exit before 1:00 p.m. — 12:30 p.m., say — and close when it hits instead of waiting for the close.
The home page's "time left until the close" and "time left until the 3:30 p.m. cutoff" are computed for a 4:00 p.m. close, so on a half day they overstate by 3 hours and 2.5 hours — don't trust them; count down to 1:00 p.m. yourself.
The 3:55 p.m. close-out reminder won't appear that day — quotes freeze near 1:15 p.m. and never reach 3:55 p.m.; no reminder doesn't mean no need to close.
Try the rhythm once with 1 long single-leg contract: open after the 10:30 p.m. Beijing open, close before 2:00 a.m., and walk through a half day once before anything else.
This simulator uses real CBOE option chains delayed about 15 minutes, starts with $10,000 in virtual funds, charges $0.65 per contract per side in fees, and shows P&L net of fees; short-sale margin is a simplified simulated rule at 20% of the strike, not a real broker margin. The simulator is for practicing orders, discipline, and review. It is not investment advice and promises no returns.