How to count days between dates
The number of days between two dates is simply the later date minus the earlier one. Whether you count the final day depends on the situation — for a hotel stay you usually don't count the checkout day, but for an event countdown you might.
What are business days?
Business days count only Monday to Friday, excluding weekends. They're useful for estimating delivery times or project deadlines. (Public holidays vary by country and aren't removed here.)
Does it include the start date?
The plain day count is end minus start. Tick "include the end day" to count both endpoints — useful for things like counting vacation days.
Why is the month count approximate?
Months have different lengths, so a single "months" figure is an average. The years-months-days breakdown above it is exact.