Date & Working Days Calculator
Count days between dates or add and subtract working days (Monday–Friday). Optionally exclude national public holidays when adding or subtracting days.
This date calculator helps you find the number of days between two dates and to add or subtract a number of days, weeks, months, or years from any date. You can optionally use business days (weekdays only) when adding or subtracting days. Below you will find detailed information about the Gregorian calendar, leap years, and how dates are used in daily life and business.
Frequently Asked Questions About Dates and Calendars
How are days between two dates calculated?
We take the two calendar dates (start and end), normalize them to midnight, and count the number of 24-hour periods between them. The result is a whole number of days. We also show how many of those days are weekdays (Mon–Fri) and how many are weekend days.
What does "business days" mean when adding to a date?
When you add "N business days" to a date, we move forward (or backward if subtracting) and count only weekdays—we skip Saturdays and Sundays. So "5 business days" from a Wednesday is the following Wednesday (if no holidays). Public holidays are not excluded in this calculator.
Why does the number of days in a month vary?
Month lengths were set by historical convention. February has 28 days (29 in leap years) because of how the Roman calendar was adjusted. The other months alternate between 31 and 30 days (with July and August both having 31) to reach a total of 365 or 366 days per year.
Is the Gregorian calendar the same everywhere?
The Gregorian calendar is used for civil purposes in almost every country. Some countries also use other calendars for religious or cultural events. When we say "date" in this tool, we mean the Gregorian calendar date.
Can I add or subtract weeks, months, or years?
Yes. You can add or subtract days, weeks, months, or years. For weeks, we add or subtract 7 days per week. For months and years, we adjust the month and year, and the day is kept when possible (e.g. Jan 31 + 1 month = Feb 28 or 29). Business days only apply when the unit is "days."