Add or subtract months from a date
Suits monthly instalments, renewals and contract terms that are set in months rather than days.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter date, operation and number of months.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
The month moves by the given count, carrying into the year; the day number stays, or becomes the last day of the new month if that month is shorter.
Example
Inputs: Date = 2024-01-31, Operation = Add, Number of months = 1 months. Result: Resulting date: Thursday, February 29, 2024 (2024-02-29); Day of the week: Thursday; Difference in days: 29.
Limits and caveats
- When the new month is shorter the last day is used, so adding then subtracting may not return the original day.
- Months here are Gregorian, not Hijri.
Questions about this tool
What is 31 January plus 1 month?
It is 28 February, or 29 in a leap year, since February has no 31st.
Is a month always 30 days?
No, it moves to the same day of the target calendar month, so the day count depends on the months crossed.
How do I find my last instalment date?
Enter the first instalment date and add the number of instalments minus one, in months.