What this calculator does
This calculator answers the "N months from today" question for any number of months, in either direction. Enter how many months and whether that is forward or backward from the starting date, and it works out the resulting calendar date, including the day of the week it falls on.
The tricky part of adding or subtracting months is what happens when the starting day does not exist in the target month, such as adding a month to 31 January. This calculator clamps the result to the last valid day of that month, so 31 January plus one month lands on 28 February in a common year rather than overflowing into March.
The formula
The starting date is shifted forward or backward by the chosen number of calendar months, keeping the same day of month where possible. If that day does not exist in the target month, the result is clamped to the last day of that month instead of rolling over into the following one.
| Term | Meaning |
|---|---|
| Starting date | The date the count runs from, defaulting to today. |
| N | The number of whole calendar months to shift by. |
| Direction | Whether the shift runs forward (after) or backward (before) from the starting date. |
The inputs explained
| Field | What to enter |
|---|---|
| Starting date | The date to count from. Defaults to today but can be set to any past or future date. |
| Number of months | How many months to shift by. 6 is a common choice, but any whole number works. |
| Direction | Choose whether the target date falls after or before the starting date. |
When to use it
Working out a review or renewal date
Contracts, subscriptions and medical follow-ups are often scheduled a fixed number of months out from a given date, which is exactly what the forward direction here calculates.
Checking a stated eligibility window
Rules that reference a cut-off "N months before" a given date, such as a visa or benefit condition, are answered directly by the backward direction rather than counting days by hand.
Comparing several offsets at once
Running the same starting date at 3, 6, 9 and 12 months out is a quick way to see a run of upcoming milestone dates without recalculating each one separately.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
Where common month offsets land, forward from today
A range of month counts, all measured forward from today.
| Months forward | Target date | Day of week |
|---|---|---|
| 1 | 23 Sep 2026 | Wednesday |
| 3 | 23 Nov 2026 | Monday |
| 6 | 23 Feb 2027 | Tuesday |
| 9 | 23 May 2027 | Sunday |
| 12 | 23 Aug 2027 | Monday |
| 18 | 23 Feb 2028 | Wednesday |
Six months forward versus six months back
The same 6-month offset, run forward and backward from today.
| Direction | Target date | Total days between |
|---|---|---|
| After today | 23 Feb 2027 | 184 |
| Before today | 23 Feb 2026 | 181 |
Questions
What happens if the starting day does not exist in the target month?
The result is clamped to the last day of that month rather than spilling into the next one. Adding one month to 31 January gives 28 February in a common year, or 29 February in a leap year, not 2 or 3 March.
Can I use this to count months backward from today?
Yes, set the direction to "before the starting date." Six months back from a date in early spring lands in the previous autumn, for example, using the same month-shifting logic run in reverse.
Does this give the same answer as counting 30-day blocks?
No, and that is deliberate. This calculator shifts by whole calendar months, so the resulting date keeps the same day of month wherever possible, rather than approximating a month as a fixed 30 days, which drifts against the real calendar over several months.
Can I use a date other than today as the starting point?
Yes, the starting date field accepts any date, past or future. Today is just the default, since that is the most common use, but the calculation works identically from any starting date.
For a whole-months-and-days breakdown between two known dates instead of a single offset from today, see the months calculator. For a straight day count to a specific target date, use the days until calculator.