What does “on-time” actually mean?
“On-time” has a precise legal meaning in U.S. flight data — and it is more forgiving than most travelers assume. Here is exactly what counts, and what doesn’t.
Last reviewed June 21, 2026
The rule
The 15-minute standard
A flight is “on-time” in U.S. government statistics if it arrives less than 15 minutesafter its scheduled arrival time. A flight 14 minutes late still counts as on-time; one 15 minutes late is counted as delayed. This is the U.S. Department of Transportation’s ArrDel15 measure, and it is exactly the definition every figure on OnTimeStats uses.
At the gate
Measured at the gate, not the runway
The clock is the gate arrival time, not the moment the wheels touch the runway. A flight can land early and still be recorded as late if it then waits for a gate to open up. The same gate-based, 15-minute rule applies to departures too.
What's excluded
Cancelled and diverted flights are counted separately
Cancellations and diversions are not folded into the late-arrival rate — they are reported in their own categories. That matters: an airport or airline can post a strong on-time rate while still cancelling a meaningful share of flights. That is why we always show cancellation rates alongside on-time figures rather than letting a clean on-time number tell a misleading story.
Coverage
Which flights are in the data
The figures come from larger U.S. airlines — those with at least 0.5% of total domestic scheduled-passenger revenue (a threshold lowered from 1% for flights on or after January 1, 2018). Since 2018, the data also covers the regional partners that operate flights under those airlines’ brands, so codeshare regional flying is included rather than hidden. The exact list of reporting carriers shifts over time as revenue shares change.
Sources
Keep reading