Date range
Count completed calendar months first, then the remaining days.
Months Between Dates Calculator
Calculate full months and remaining days between two dates, with total days, approximate months, and start/end weekdays.
How this months between dates calculator works
Enter a start date and an end date. The main result counts completed calendar months first, then shows the remaining days after the last completed month.
Month lengths vary, so the supporting approximate-months result is separate from the completed-month count. End-before-start ranges are labelled clearly instead of being hidden as zero.
The month anchor uses the last valid date when a target month is shorter. For example, January 31 to February 28 is one completed calendar month. The approximate figure divides elapsed days by the average Gregorian month length and is labelled separately.
When months and days are useful
Use this calculator for project planning, tracking elapsed months, personal date planning, rough planning periods, and comparing date ranges. It is not a contract, billing, rental, legal, or deadline authority.
Related date calculators
For elapsed calendar days, use the date duration calculator. For full weeks and remaining days, use the weeks between dates calculator. To add or subtract months from a date, use the date calculator. To count days remaining until a target date, use the days until calculator. To calculate age-style years, months, and days, use the age calculator.
Months between dates FAQ
What does full months and remaining days mean?
The calculator counts completed calendar months first, then counts the remaining calendar days after the last completed month.
Why are months not all the same length?
Calendar months range from 28 to 31 days, so completed months can differ from a simple total-days divided by 30 estimate.
How are end-of-month dates handled?
The completed-month anchor clamps to the last valid day when the target month is shorter, so January 31 to February 28 is one completed calendar month.
Can I use this for billing, leases, or contracts?
No. It is a date-math helper for planning and comparison, not a billing, rental, legal, contract, or deadline system.