An automated strategy has no sense of time. It will act on a signal at 3 a.m. in a thin overnight book exactly as it would at 10 a.m. in the busiest part of the day. A trading hours window is how you tell it which part of the session you actually want it to trade.
Why the time of day matters for order flow
Order-flow signals read the behaviour of other participants, and who is participating changes through the day. The same ratio or stack means different things at different times.
- Overnight. Fewer participants and thinner books. A handful of contracts can make one side of the book look heavy, and a single order can create a footprint imbalance.
- The cash open. Volume jumps, spreads of opinion are wide and price often rotates hard before it picks a direction.
- Late morning. Usually still active and often two-sided, which suits book-based scalping.
- Midday and afternoon. Activity can drop off, then pick up again into the close.
None of this is a rule. It is a reason to decide on purpose rather than leave the strategy running whenever the exchange is open.
BookPilot's window
BookPilot has a built-in window controlled by three settings. All times use the HHmmss format in exchange time, which for CME futures is Chicago time.
| Setting | Default | Suggested |
|---|---|---|
| Use Trading Hours | On | On |
| Start Time | 083000 (the US cash open) | 083000 - 090000 |
| End Time | 150000 | 110000 - 150000 |
A few details are worth knowing before you change anything:
- The window only controls new entries. It never closes an open position, so a trade taken at 14:59 still runs to its bracket.
- Separately, BookPilot closes open positions 30 seconds before the session ends.
- If End Time is earlier than Start Time, the window wraps around midnight and runs overnight.
- Turning Use Trading Hours off lets it trade any time the session is open, including the thin overnight books described above.
The guide's Conservative profile ends at 110000, keeping only the morning. The Balanced and Active profiles keep the full 15:00 default. Starting a little later, around 090000, skips the first half hour of opening volatility if your testing shows that period hurts.
FlowPilot has no clock window
FlowPilot does not have a trading hours setting. The FlowPilot vs BookPilot comparison lists the trading-hours window as BookPilot only. FlowPilot gives you other ways to shape when it trades:
- Open Warm-up Bars. In Auto mode, the regime is forced to Regression (fade) for the first bars of each session, 3 by default. That changes how it trades the opening rotation, but it does not stop it trading.
- Manual arming. In Follow or Fade mode, FlowPilot only trades after you press Arm Long, Arm Short or Arm Both, and disarms after each entry. If you only arm during the hours you choose, it only trades then.
- Disabling the strategy. The plainest option: enable it when your session starts and disable it when you are done.
Picking your own window
Treat the window as something to test, not something to guess. A practical approach:
- Run BookPilot in Market Replay over several days with the default 08:30 to 15:00 window.
- Note the time of each trade and whether it won or lost, along with the reasons on the panel's Blocked line.
- Look for stretches of the day where results are consistently poor or signals are mostly blocked.
- Narrow the window by one change at a time and replay the same days again.
Keep in mind that a narrower window means fewer trades, so each day carries less information. Give any change enough sessions before you judge it.
Windows and account rules
If you trade an evaluation or funded account, check whether your firm has rules about holding positions near the close or around scheduled news. The window and the 30-second pre-close exit help, but they are not a substitute for reading your firm's current rules.
Trading futures can lose you more than you expect, at any hour. Prove out a new trading window in SIM and Market Replay before running it on an evaluation, funded or live account.