Date calculator (± days)
Add or subtract days, weeks, months from a date.
- Instant
- Free
- Private (processed locally)
- No sign-up
“What date is it in X days?” — instant answer
30-day payment terms, 90-day trial periods, 14-day return windows, an appointment “in 6 weeks”… We all regularly need to project a date. This calculator works both ways: forward (add) and backward (subtract), with any combination of years, months, weeks and days.
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Pick the start date
Today by default — freely changeable, in the past or the future.
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Add or subtract
Toggle between + and −, then fill in the fields you need: years, months, weeks, days.
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Read the result
The full date with its weekday, plus its ISO form (YYYY-MM-DD) for your documents.
Common time periods worth knowing
| Period | Typical use |
|---|---|
| 14 days | Withdrawal right (online purchases, EU) |
| 30 days | Standard business payment terms |
| 60 / 90 days | Negotiated payment terms, trial periods |
| 6 months | Validity of many quotes and prescriptions |
| 1 year | Warranties, subscriptions, contract anniversaries |
Month addition is calendar-based: “March 31 + 1 month” gives May 1 when the target month has only 30 days. This is standard calendar behavior — double-check end-of-month dates for contractual deadlines.
Frequently asked questions
What date will it be in 30 days?
Keep today as the start date, type 30 in the Days field and read the result: the exact date with its weekday — handy for payment terms or return windows.
How does the tool handle months of different lengths?
Years and months are added calendar-wise: January 31 + 1 month gives March 2 or 3 (depending on the year), since February is shorter. Weeks and days are then added as exact days.
Are leap years taken into account?
Yes. The calculation relies on the real Gregorian calendar: February 29 appears when it should, and year transitions are handled correctly.
Can I combine several units?
Yes: 1 month + 2 weeks + 3 days in a single operation. Years and months are applied first, then weeks and days, in the order of the form.
How do I count business days?
This tool counts calendar days. For business days, a simple rule: 5 business days ≈ 7 calendar days. For a precise count between two dates, use our date difference calculator.