Add to Date Calculator
Want to know what date it will be in 30 days, 6 weeks or 3 months? Enter your start date, the amount and the unit.
Result
Fill in the fields to see your result.
Formula
Result = start date + (amount ร unit)
For days and weeks, the calculator simply adds the number of days. For months, the calendar month shifts forward; if the start date doesnโt exist in the target month (for example 31 January plus 1 month), the date is clamped to the last day of that month (28 or 29 February) rather than overflowing into March.
Worked examples
15 January 2026 plus 10 days
โ 25 January 2026.
31 January 2026 plus 1 month
โ 28 February 2026 (not 3 March).
Common mistakes
- Expecting that adding months at the end of a month always lands on the same day next month.
When to use it
- Calculating the expiry date of a contract or warranty.
Frequently asked questions
Can I also calculate backwards?
Yes, enter a negative amount to subtract days, weeks or months from the date.
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