Date Calculator: Days Between Dates and Working Days

Count the days between two dates, including business days

The gap runs from the start date to the end date without counting the last day, unless you tick “Include end date” (+1 day). From 1 to 31 May 2026 inclusive you get 31 days, 20 of them business days in the United States: 21 weekdays minus one federal holiday, Memorial Day on Monday 25 May.

What the tool calculates

• Duration in years, months and days, plus totals in days, hours and weeks (days ÷ 7, one decimal). Dates are read in local time at the time entered (00:00 by default).
• Business days: every Monday to Friday that is not a public holiday, from the start day included to the end day excluded (included if the box is ticked).
• Adding or subtracting days, business days, weeks, months or years; an age tab and a day sheet (weekday, leap year, Chinese, Islamic and Hebrew calendars).

Example

From Friday 1 May to Sunday 31 May 2026, box ticked: 31 days, or 4.4 weeks. May 2026 has 21 weekdays, and one of them is a US federal holiday, Memorial Day on Monday 25 May: 20 business days. In add mode, Friday 1 May 2026 + 5 business days gives Friday 8 May: the start day is not counted and the weekend is skipped.

Holidays and limits

The tool covers 7 countries and uses the country of the page language by default, here the United States. It removes the 11 federal holidays, 10 of which fall on a weekday in 2026 (Independence Day is on Saturday 4 July). Six follow a weekday rule: third Monday of January (Martin Luther King Jr. Day) and of February (Presidents’ Day), last Monday of May (Memorial Day), first Monday of September (Labor Day), second Monday of October (Columbus Day) and fourth Thursday of November (Thanksgiving). The country selector also offers France (11 statutory holidays), England and Wales (8 bank holidays), Germany (9 nationwide holidays), Spain (10 national holidays), Brazil (10) and Italy (12). State and regional holidays (German states, Spanish autonomous communities, Alsace-Moselle) are not deducted, and neither are substitute days when a holiday falls on a weekend: the federal day off on Friday 3 July 2026 counts as a business day.

• Totals follow clock time: the switch to daylight saving time, where it applies, does not drop a day (151 days from 1 January to 1 June 2026), but the total in hours can differ by one hour from the time actually elapsed.
• Adding 1 month to 31 January 2026 gives 3 March, because February has only 28 days.
• The week number follows ISO 8601 (week 1 contains the year’s first Thursday): 14 October 2026 is in week 42.

Sources and dates: United States: OPM, Federal Holidays; France: French Labour Code, art. L3133-1 (in force since 10 August 2016) and service-public.fr, public holidays in the private sector; United Kingdom: GOV.UK, Bank holidays; Germany: Federal Ministry of the Interior (BMI), national holidays; Spain: BOE, 2026 public holidays; Brazil: Ministry of Management, 2026 holiday calendar (Portaria MGI nº 11.460/2025); Italy: Normattiva, Law 260/1949, art. 2 (checked 27 October 2026).

Frequently Asked Questions

Does the count include the first and last day?

By default the start day is counted and the end day is not: 1 to 31 May gives 30 days. Tick “Include end date” to get 31 days, as for a contract or rental period.

How many business days are there in May 2026 in the United States?

May 2026 has 21 weekdays. Only one federal holiday falls on a weekday, Memorial Day on Monday 25 May, leaving 20 business days.

How do I add business days to a date?

Open the add tab, choose the “Business days” unit and the country. The tool steps day by day, skipping weekends and holidays: in the United States, Friday 1 May 2026 + 5 business days gives Friday 8 May.

What happens when I add one month to 31 January?

The tool rolls the overflow into the next month: 31 January 2026 + 1 month gives 3 March, since February has 28 days. For a contractual deadline, check the rule set by the contract (often the last day of the month).

Is this tool really free?

Yes, all tools on Kristools are 100% free and accessible without registration.

Is my data protected?

Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.