Date Calculator
Two everyday jobs: how far apart are two dates, and what date is N days from now.
Days between two dates
Add or subtract days
Counting days correctly
The classic off-by-one: Monday to Friday is 4 days apart but 5 days inclusive. This calculator reports the difference (end minus start) — the convention used for deadlines, interest accrual and project durations. If your context counts both endpoints ("a 5-day festival, Monday through Friday"), add one.
Weekdays vs. business days
The weekday count above excludes Saturdays and Sundays but not public holidays, which vary by country and year. For legal or payroll deadlines defined in "business days", subtract any holidays in the window manually — and note some jurisdictions have their own counting rules for when the clock starts.
Everyday uses
- Notice periods: 30/60/90 days from a letter's date — use the add-days tool.
- Returns & warranties: "within 30 days of purchase" — count from the receipt date.
- Pregnancy & medical: appointments and milestones are set in exact day/week counts.
- Project planning: the weekday count gives you actual working time between milestones.
Deadlines where the count matters
| Situation | Typical period | Counted from |
|---|---|---|
| Employment notice | 2–8 weeks | Date the written notice is given |
| Retail returns | 14–30 days | Date of purchase or delivery |
| Rental notice to vacate | 30–60 days | Usually the next rent due date, not the day you give notice |
| Contract cooling-off | 3–14 days | Date of signing |
| Invoice terms (Net 30) | 30 days | Invoice date, unless stated otherwise |
| Passport renewal advice | 6 months validity | Date of intended travel, not booking |
The rental one catches people constantly: giving 60 days' notice on 10 March usually doesn't mean leaving on 9 May — it means the notice period starts from the next rent date, so you're out at the end of May. Check the exact wording of your agreement rather than assuming.
Inclusive vs exclusive counting
This is the classic off-by-one. Monday to Friday is 4 days apart but 5 days inclusive. This calculator reports the difference (end minus start), which is the convention for deadlines, interest and durations. If your situation counts both endpoints — a five-day festival running Monday to Friday, or hotel nights versus days — add one. When a contract says "within 30 days", it almost always means the difference count, but the safe move is to act before day 29 and never test it.
Business days aren't just weekdays
The weekday figure above excludes Saturdays and Sundays but not public holidays, which vary by country, province and year. For a legal or payroll deadline expressed in business days, subtract the holidays that fall inside your window. Some jurisdictions also have their own rules about when the clock starts — a deadline given on a Friday afternoon may not begin until Monday.