Invoice Due Date Calculator

Add or subtract days from a date to calculate the exact future or past date.

⚙️ Calculation Parameters

Start date:

Number of days to calculate:

Calculation direction:

Forward (+ Add days)Backward (- Subtract days)

Which days are counted?

Calendar days (all days of the week, including weekends)
Business days (strictly Monday to Friday, weekends skipped)

Counting method:

Standard (start date not counted)
Include start date (start date is counted as the first day)

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Invoice Due Date Calculator

🎯 Calculation Result

Start date: 04.09.2026 (Friday)
Final result:

04.10.2026.

Sunday

Applied criteria:
After adding 30 calendar days.

💡 Note: This calculator is an excellent tool for calculating payment due dates, delivery deadlines, or court deadlines. If "Business days" is selected, Saturdays and Sundays are completely skipped when adding days.

⚠️ The calculation is for informational purposes only and cannot be used as an official document.

Isplate.info – Your business assistant!

Invoice Due Date Calculator

⚙️ Calculation Parameters

Invoice Due Date Calculator

🎯 Calculation Result

Start date: 04.09.2026 (Friday)Final result:

Start date: 04.09.2026 (Friday)
Final result: