Which line has the tightest arrival window, not just the best average?
Sort lines by typical arrival and by the gap between their fastest and slowest days.
Parameters last checked · defaults are templates, not quotes.
Two lines can share a 12-day average and behave nothing alike. One arrives between day 9 and day 14; the other between day 5 and day 24.
If you have a deadline — a trip, a birthday, a resale listing — the width of the window matters more than the midpoint, and this page makes the width the primary column.
Rows are sorted by typical arrival, so the top entry is the earliest line rather than the most predictable one. A quick line and a tight line are different claims, and the window column is where the second appears. Read down that column instead of stopping at the first row, and treat the mean width as a summary of the set you typed: removing the widest line lowers the mean while no carrier has changed its schedule. Quote it as a property of your list, not of the routes.
Nothing in the check between fastest, typical and slowest verifies where those figures came from; the tool only rejects a row whose middle value falls outside the two ends. If the three numbers were copied from different pages — a carrier average here, a rounded range there — the row passes and the window it produces means little. Confirm that one published table supplied all three for the same service, and enter the range as printed rather than narrowing it. Published ranges are not verified here; they are taken at face value.
Transit window comparison
Published ranges
Window comparison
Mean window width
12.7 days
A narrow window is worth a premium when you have a deadline.
| Line | Typical | Window | Flag |
|---|---|---|---|
| Express air | 7 d | 7 d (5–12) | tight |
| Economy air | 12 d | 12 d (8–20) | uncertain |
| Postal air | 16 d | 19 d (11–30) | uncertain |
How to read the result
- A gap above 10 days is flagged as an uncertain window, which is a description of the published range rather than a criticism of the line.
- Tight windows usually cost more; the table lets you decide whether the premium buys anything you need.
- Seasonality stretches windows rather than shifting them, so check the season calendar before drawing conclusions.
- Ranges are entered by you; the tool does not invent a carrier’s numbers.
- The three day figures should come from one published range for the same service, since the tool enforces only that the three days run fastest to slowest, not that they came from one source.
Formula, source and caveat
window = slowest published days − fastest published days
- Source
- The published range you enter.
- Caveat
- Published ranges are marketing ranges, not measurement.
flag uncertain when window > 10 days
- Source
- This site’s own threshold.
- Caveat
- A wide window is not a failure; it is a planning input.
Questions this tool raises
- Where do I find the fastest and slowest days?
- The line page usually quotes a range. Enter both ends rather than only the middle.
- Do weekends count?
- Published ranges usually count calendar days, including weekends and holidays.
- Why does my parcel sit at one status for days?
- Queueing at a hub or awaiting a flight is normal inside a wide window. Tracking silence is not the same as a lost parcel.