Days Calculator: Days Between Two Dates – 無料オンラインツール

Days Calculator — Count the Days Between Two Dates

This free days calculator tells you exactly how many days are between two dates, and can also add or subtract days from any date. Enter a start date and an end date to instantly see the total number of days between the two dates, plus the equivalent in weeks, the number of weekdays (business days), weekend days, and hours. Switch to the Add / Subtract tab to find out what the date will be a certain number of days from now — handy for deadlines, due dates, contracts, and countdowns.

Everything runs instantly in your browser, so your dates stay private and there is nothing to install. Use the quick buttons to jump to today, or the swap button to reverse the order of your dates. Tick “Include the end date” when you want both the start and end day counted (for example, when counting the length of a hotel stay or a project that runs through its final day).

Frequently Asked Questions

How do I calculate the number of days between two dates? Pick your start date and end date above and press “Calculate Difference”. The tool counts the days between them and also shows weeks, weekdays, weekend days and hours.

Does it count the end date? By default the end date is not included, so the result is the number of nights or full days between the dates. Tick “Include the end date” to count both endpoints.

What are “weekdays” in the result? Weekdays are business days — every day from Monday to Friday in the range, excluding Saturdays and Sundays. Public holidays are not deducted.

Is it free and private? Yes. The calculation happens entirely in your browser, no data is uploaded, and there is no sign-up or limit.