0DTE Trading-Day Timeline: Every Step from Open to Close
A 0DTE contract lives for one day. From the open to the close, every step happens at a fixed time. Learn this clock first, and you won't be scrambling in the final half hour.
9:30 a.m. ET: the open, the day begins
Regular US market hours are 9:30 a.m. to 4:00 p.m. ET, and 0DTE contracts follow that clock.
Before the open, the quotes you see are a snapshot from the previous close; they only refresh once trading starts.
This simulator's quotes are delayed about 15 minutes — the price you see is from 15 minutes ago, not this second.
At the open, check one thing first: which contract expires today, and how far its strikes sit from the spot.
During the day: time value ticks away hour by hour
A 0DTE contract expires today, so every hour that passes brings expiry one hour closer and time value a little lower.
At the close, whatever is left is settled at the settlement value — out-of-the-money goes to zero. When time runs out, time value is zero.
You don't need to watch every minute. Write your exit plan, and act when its conditions hit — that beats staring at the screen.
The simulator caps you at 3 opens per day, and a $60 daily fee total trips the circuit breaker — spend your opens carefully.
After 3:30 p.m.: close only, no new opens
After 3:30 p.m. ET, this simulator blocks new opens; you can only close positions you already hold.
From 3:55 p.m., the page reminds you to close today's positions before the close — the simulator never auto-closes, so you have to do it yourself.
Prices move fast in the last half hour, and that is exactly when beginners chase the wrong move — so the rule simply shuts the door.
On half days the market closes at 1:00 p.m., settlement is still that day's closing price, and you still have to close out yourself before the bell.
4:00 p.m.: the close, settled at the closing price
At 4:00 p.m. the market closes, and 0DTE settles at the S&P 500 official closing price for the day.
In-the-money value is the difference between the settlement value and the strike, times $100 per point, settled in cash; out-of-the-money contracts expire worthless.
The closing price is the settlement value — no separate ticker to look up: the closing price you see on a quote screen is the number used for settlement.
After the close, review: compare the closing price with your strikes, work out what holding to settlement would have been worth, then compare it with the price you actually closed at, and see what closing early cost or saved you.
How to practice this in the simulator
Before the open, write today's exit plan: where you take profit, where you cut the loss, and how many opens at most.
Use the countdown on the home page to see how many minutes are left until 3:30 p.m. — don't open anything new in the final stretch.
When the 3:55 p.m. reminder appears, close out right away; don't leave positions past the close.
Start with 1 long single-leg contract, walk through a full day on this clock, then try spreads.
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.