From a send-by date to an order plan
This tool helps make an explicit date plan when you already know a service's recommended send-by date. You supply the working weekdays, additional closure dates, processing lead time and a buffer. The result shows every step rather than presenting a single unexplained deadline. You can save the table as an HTML planning page and the order dates as all-day calendar events.
It is a backward scheduling model, not a delivery estimator. It does not know your stock availability, production capacity, destination, carrier service eligibility, weather, transit time, label creation time or pickup cutoff. Confirm those details before using or communicating a date. A calculated planning date does not turn a carrier recommendation into an arrival guarantee.
How the working-day calculation works
First, the supplied send-by date rolls back to the latest working date on or before it. A day is working only when its weekday is selected and its date is not listed as an additional closure. The buffer then moves backward by the specified number of working days. That produces the buffered dispatch date. Processing lead time moves backward again to produce the last order planning date.
The anchor day itself is not counted when subtracting a working day. An order on a Monday with two processing working days has Tuesday as day one and Wednesday as day two when both are open. A zero-day setting leaves its anchor unchanged. The app uses the same working calendar for processing, buffer and dispatch availability; it does not model separate office, warehouse and carrier calendars. If those differ, use separate plans or a more detailed scheduling system.
Try the sourced 2026 example
The example loads four USPS recommendations for the contiguous United States before December 25, 2026: Ground Advantage and First-Class Mail on December 17, Priority Mail on December 18 and Priority Mail Express on December 19. These example dates were checked against the official USPS holiday date table on October 27, 2026. USPS notes that actual delivery depends on route, acceptance time and other conditions. Check that source again; the example is not automatically refreshed and does not cover Alaska, Hawaii, territories, international or military mail.
With Monday through Friday selected, two processing days, one buffer day and no additional closures, the example produces order planning dates of December 14 for Ground Advantage and First-Class Mail, and December 15 for Priority Mail and Priority Mail Express. The Express send-by date is a Saturday, so its first working anchor rolls back to Friday before the buffer and processing steps are applied. These are the app's calculations from the example settings, not new USPS recommendations.
Use your own dates and closures
Each service needs a distinct readable name and a real send-by date. You can enter dates for your own region or carrier, provided you verify them yourself. The app does not assume that a public holiday is a closure: add every date on which your plan cannot process or dispatch. Duplicate closure entries are counted once. Closure dates are visible in the saved planning page so the assumptions can be reviewed.
Change a setting, remove a service or add a new one and the old results and download controls disappear until you build again. This prevents an earlier calendar from being offered as if it reflected an edit. Clear all removes service data, the label, closures and results, and restores the default two-day processing, one-day buffer and Monday-to-Friday calendar. Reloading clears the working session.
What the downloads contain
The calendar is an iCalendar file with one all-day event per service's order planning date. Its end date is the following day, as required for an exclusive all-day event end. It contains no alarm, invitation or automatic reminder action. It does not connect to your calendar account or create a subscription. Each build generates new event identifiers, so importing several builds can create duplicates. Delete an earlier imported plan yourself when replacing it.
Calendar events do not contain an order cutoff hour or a time zone. An all-day marker is not an instruction to accept orders until midnight. Decide the actual cutoff time and communicate it separately through your store. The HTML download contains the table and its assumptions in a self-contained document that you can open or print. Review and edit your customer communication using the verified operational details; this page does not publish a shipping policy for you.
Bounds and privacy
Dates must be between 2020 and 2100, and calculated order dates must remain in that range. Processing accepts 0–60 working days and buffer accepts 0–30. At least one weekday must be selected. There can be at most 12 services, 100 distinct closure dates and 12,000 closure-input characters. These limits keep the table and date search bounded. No timezone or daylight-saving arithmetic is needed for the date-only model.
The tool makes no background carrier, store or calendar requests. Settings and results stay in page memory rather than browser storage. Saving a file creates a separate copy on your device; clearing this page does not remove that download or any calendar events you later import. Normal hosting requests for this page are separate from the local planning calculation.