Contracts, notices, legal filings and project plans often specify deadlines like “30 days after receipt” or “10 business days before”. Whether weekends count changes the date by days. Public holidays are not included here – check them separately.
How to use the Deadline Calculator
- Start date
- Amount of time
- Unit
- Deadline is
- If it falls on a weekend
Results update as you type, and every field accepts the units shown in its menu.
How it works
Choose the start date, the amount of time and its unit, whether the deadline is before or after the start, and whether to move weekend deadlines.
Tips
- Track a typical week before planning – real figures beat estimates.
- Break big tasks into smaller pieces and plan buffer time for interruptions.
- Re-run the numbers when your inputs change so plans stay realistic.
- Use results as a guide for decisions, not as a precise prediction.
Common mistakes to avoid
- Counting calendar days when the deadline is in working days (or the reverse).
- Forgetting breaks, setup and handover time.
- Assuming every day is as productive as your best day.
Inputs explained
| Field | What to enter |
|---|---|
| Start date | A date |
| Amount of time | A number |
| Unit | Choose one: Calendar days, Working days (Mon–Fri), Weeks, Months … |
| Deadline is | Choose one: After the start date, Before the start date |
| If it falls on a weekend | Choose one: Move to the nearest working day, Keep the date |
What each result means
- Day of the week = weekday([Deadline])
- Calendar days from start = abs([Deadline] – [Start date])
- Working days from start = abs(workdays(min([Start date], [Deadline]), max([Start date], [Deadline])))
Formula
Calendar units: deadline = start ± time (months added by calendar date)Working days: count Monday–Friday onlyWeekend rule: after → move Saturday/Sunday to Monday; before → move to FridayWorked example
Inputs — Start date: 2026-10-25; Amount of time: 30; Unit: Calendar days; Deadline is: After the start date; If it falls on a weekend: Move to the nearest working day.
Results — Deadline = Tue, November 24, 2026; Day of the week = Tuesday; Calendar days from start = 30; Working days from start = 21.
Frequently asked questions
What is 30 days from today?
Enter today and 30 calendar days; the calculator shows the date and weekday.
Do business days include holidays?
No – this counts Monday to Friday only; subtract public holidays yourself.
How are months counted?
By calendar date: one month after 31 January is the last day of February.
What formula does the Deadline Calculator use?
Calendar units: deadline = start ± time (months added by calendar date).