Count exactly how much time separates two dates. Pick a start date and an end date, and the calculator shows the gap as a total number of days, and also broken down into years, months and days, plus the equivalents in weeks and hours. There is an option to include the end date in the count, which matters when you are counting things like billing periods or event days rather than a pure duration. It correctly accounts for leap years and the differing lengths of months, so the result is precise rather than an approximation. This is useful for deadlines, anniversaries, project timelines, notice periods and age gaps. Everything is calculated locally in your browser, and no dates are ever sent anywhere.