Know which suburbs you can truly promise next day.

What is Cutoff Promise Checker, and what is it not?

It is a promise mapper for a small store that packs and posts its own orders. You give it your dispatch cutoff and the timezone it is meant in, the carrier transit table for the zones you ship to, your origin postcode, your target postcodes and the date a customer actually needs the parcel. It returns a suburb by suburb map that says, for each destination, whether "order by 2pm, get it tomorrow" is true, the service tier and the transit days that verdict came from, a corrected cutoff clock per zone, a plain fallback line for orders placed after the cutoff, and an audit of the promise you have already written on your own policy page with corrected wording to paste back.

It does not track a parcel, chase the carrier, refund a delivery fee, set your shipping rates, book a pickup or print a label. It does not read your live orders: the first value is the paste, and an integration is a later paid tier. It never guarantees a delivery date, because carriers publish transit times as estimates and exclude a guarantee. It maps the promise and names the basis, and it says plainly when an input is missing rather than filling in the optimistic answer.

How the map is built

The transit table is held at build time from the carriers' and aggregators' published speed and coverage pages, each zone carrying the service tier it names, and it is dated. Where a carrier publishes a range, the map uses the slower end, so a next-day verdict is only given where the whole range supports it. The dispatch day walks forward past a weekend and past a public holiday at your origin. A remote zone, a signature requirement, a seasonal cut-off window and a manual override each add their days before any verdict is shown. The same inputs always give the same map.