Calendar difference vs total days

A date span can be expressed in two different ways. A calendar difference answers in years, months and days. A total-day difference counts the number of midnight boundaries between the two dates. Both are shown because they answer different practical questions.

What else is included

The result also shows complete weeks plus leftover days and the number of Monday-to-Friday weekdays in the interval. Leap years and the different lengths of calendar months are handled automatically.

Inclusive counting

By default, the total-day result measures the elapsed span between the two dates. Turn on inclusive counting when you need both boundary dates counted. This option changes the total-day and weekday counts; it does not redefine the calendar year-month-day decomposition.