Date differences
Month calculator
Count completed calendar months and total elapsed days between dates.
How to use this calculator
Enter Start date and End date. Count completed calendar months and total elapsed days between dates. The answer updates when you change an input.
Understanding the result
Calendar months have unequal lengths, so the whole-month result is not calculated by dividing days by 30.
Common questions
What assumptions does this result use?
If dates are reversed, they are reordered before calculation.
Are intermediate values rounded?
No. The calculation retains JavaScript number precision internally and formats only the displayed result unless the stated method requires a discrete whole value.