Add Months to Date Calculator
Add or subtract whole calendar months with end-of-month clamping.
General-use notice: This calculator performs mathematical/date calculations only. Legal deadlines, notice periods, limitation periods, interest and compliance rules can vary by jurisdiction, contract, authority and case. Verify the applicable rule before relying on the result.
How to use this calculator
What to enter
Enter or select the following as requested: Start date; Months to add (negative allowed). Follow the units, valid ranges, examples, and options displayed beside each field.
What the result means
The date or duration result is calculated from the entered dates, times, calendar rules, and exclusions. Check inclusive versus exclusive counting, time zone, daylight-saving changes, and whether weekends or holidays are excluded.
When to use it
Use this to plan a date, measure elapsed time, or estimate a deadline. Verify the relevant calendar, location, and legal or workplace rules when they affect the answer.