Invoice Due Date Calculator

How to use this calculator

Enter the invoice or receipt date specified by the agreement. Choose net days or days after the invoice month end, then the number of calendar days. Optionally add a discount window and a working-day adjustment for payment.

The anchor is day zero. Payment dates can stay unchanged or move to the previous or next eligible day using your workweek and closures. The discount date is counted from the invoice date and is not adjusted. A discount deadline after the final payment date is rejected. No supplier terms, grace periods or legal deadlines are inferred.

A worked example

An invoice dated November 1, 2026 with Net 30 terms is due December 1. A ten-day discount window ends November 11. Under month-end plus 30 days, the nominal payment date is December 30.

Do Net 30 terms always mean 30 business days?

This tool's Net N mode uses calendar days. Apply it only when those are your agreed terms. For an explicitly working-day term, use Add Business Days with the correct calendar.

Further reading: Zoho invoice due-date help. Your entered rules determine this result.

Which calendar and years are supported?

Use Gregorian dates from 1900 through 2100. Each tool shows its own range and counting rules. Calculations run in your browser when requested, with no background polling. Today buttons use the server's current date in your browser's time zone. Calendar downloads contain all-day planning markers; review them before importing.

What happens to my dates?

Calculations run on your device. Saving a calculation is optional and keeps it in this browser. A setup link contains the dates and settings you entered; anyone with the link can read them. Use one tab per saved calculator. Clear saved data from Privacy & settings.