How date adder works
Adding time to a date is not as simple as adding numbers, because months have different lengths and leap years add an extra day every four years. A date adder handles these calendar rules so the result lands on a real date — for example, adding one month to January 31 gives February 28 or 29, not March 3.
This calculator adds (or subtracts) years, months, weeks, and days from a start date using the calendar's own rules. It applies year and month changes first, then adds the day and week offsets, so combinations like "+1 year 2 months 10 days" work correctly. It also reports the total day difference between the start and result.
Pick a start date, enter the offsets, and choose add or subtract. The tool returns the resulting date and the day count between the two. Use it for deadlines, due dates, contract end dates, and any "what date is N days from now" question.