Date Difference Calculator

Years are subtracted first, then months, then days. If the day of the month comes out negative, one month is borrowed and the real length of the previous month is added - which is why January 31 to March 1 is one month and one day, not thirty-one days. The totals underneath come from a straight subtraction of the two dates in UTC.

Why is the answer not just days divided by 30?

Because months are not 30 days. Dividing gives an approximation that drifts by several days a year. Counting whole months and then the leftover days is how a calendar actually works, and it is what a lease or a contract means by "three months".

What is the difference between this and the days between dates page?

The arithmetic is the same. This page leads with years and months, which is what you want for an anniversary, a tenure or a lease. The other leads with a single day count, which is what you want for a deadline.

How is January 31 to February 28 counted?

As 28 days, which is zero months and 28 days, because February never reaches a 31st. Add one more day and it becomes exactly one month, on March 1.

Does the order of the dates matter?

No. If the second date is earlier, the two are swapped and the gap is reported as a positive amount.