Date Calculator
Add or subtract a number of days from a date and see the resulting calendar date.
Enter your details
Your result
Enter your details to calculate.
Worked example
Sample inputs
- Starting date
- 2026-01-01
- Number of days
- 30
- Operation
- Add days
Calculated date: 31 January 2026
- Starting date: 1 January 2026
- Days: +30
How this date calculator works
The selected number of whole days is added to or subtracted from the starting date in UTC calendar arithmetic, avoiding daylight-saving time shifts.
Frequently asked questions
Does this calculator include the start date?
It moves forward or backward by the exact number of days entered; the starting date is day zero.
Can I use a number of days across a year boundary?
Yes. Month lengths, leap days, and year changes are handled by the calendar date calculation.