Business Days Calculator

DateMath steps through the range one day at a time and counts Monday to Friday, skipping the US federal holidays on the days they are observed. The start date counts only when you tick "Count the start date too", which matches Excel's NETWORKDAYS; adding business days never counts the start date, like Excel's WORKDAY.

• US federal holidays. DateMath skips the 11 annual holidays of 5 U.S.C. 6103 on the days they are observed for federal employees, as the US Office of Personnel Management (OPM) lists them: a Saturday holiday on the Friday before, a Sunday holiday on the Monday after. Source: 5 U.S.C. 6103, OPM federal holidays.
• The Gregorian calendar. DateMath treats every date as a Gregorian date, with its leap-year rule: a year divisible by 4 is a leap year, except century years not divisible by 400, so 2000 had a February 29 and 2100 will not. Source: Gregorian calendar.

DateMath's date math is tested against more than 100 cases worked out by hand. Every worked example and table on the site is computed with the same code the calculators run, so a page and its calculator can't disagree.

DateMath counts the business days, or workdays, between two dates: every Monday to Friday after the start date up to and including the end date, minus the US federal holidays on the days they are observed. That fits deadlines that leave out the day of the event, such as “within 10 business days of receipt.” Tick “Count the start date too” when the first day is itself a workday that counts, as when a job starts that morning.

From Monday, March 1, 2027 to Friday, March 5, 2027 is 4 business days; with the start date counted, it is 5 business days. If the end date is before the start date, the count is negative. Next to the answer you see the calendar days counted, the weekend days and every holiday skipped, by name and date.

For calendar days, weeks and months, use the date calculator; to add hours and minutes to a date and time, the time calculator.

1. Find the calendar days from the start to the end date (the end date minus the start date).
2. Split them into whole weeks: each whole week has 5 weekdays.
3. Count the weekdays among the days left over.
4. Subtract every holiday that falls on one of those weekdays.

Example: from Monday, January 4, 2027 to Friday, February 19, 2027 is 46 calendar days. That is 6 whole weeks (30 weekdays) plus 4 days, 4 of them weekdays: 34 weekdays in all. Martin Luther King Jr. Day on Monday, January 18, 2027 and Washington's Birthday (Presidents' Day) on Monday, February 15, 2027 are holidays, which leaves 32 business days, the same answer the calculator gives.

To find the date a number of business days away, DateMath steps one day at a time and counts only business days. The start date itself never counts, and a start on a weekend counts from the next business day. 10 business days after Monday, November 15, 2027 is Tuesday, November 30, 2027. Choose “Subtract (−)” to count backward: 5 business days before Monday, January 3, 2028 is Thursday, December 23, 2027, skipping Christmas Day on Friday, December 24, 2027 and New Year's Day on Friday, December 31, 2027.

Each count runs from the first to the last day of the month, both included. “Weekdays” is Monday to Friday; “Business days” also leaves out the federal holidays. Under today's 11 federal holidays, every year from 2021 on has 260 to 262 weekdays and 249 to 251 business days.

These are the days the calculator skips. A holiday that falls on a Saturday is observed on the Friday before, one on a Sunday on the Monday after, as for federal employees. A Saturday New Year's Day therefore moves to December 31 of the year before: New Year's Day 2028 is observed on Friday, December 31, 2027. That puts 12 observed holidays in 2027 and 10 observed holidays in 2028.

Martin Luther King Jr. Day is counted from 1986 and Juneteenth from 2021, the years they were first observed. All other holidays follow today's rules in every year, so counts before 1978 can differ from the holidays observed then. State, local and company holidays are not included.

The Federal Reserve Banks close on the same 11 holidays, with one difference: when a holiday falls on a Saturday, they stay open on the Friday before, while federal offices close that day. A Sunday holiday closes both on the Monday after. So for a bank or a payment that runs on the Federal Reserve calendar, add one business day for every such Friday in your range.

Untick “Skip US federal holidays (as observed)” to count weekdays only: every Monday to Friday counts, holidays included. Use it for a business that stays open on federal holidays, or for another country, then subtract its public holidays yourself. State, local and company closures are not built in either; subtract those from the result.

The calculator always treats Saturday and Sunday as the weekend, so it can't count six-day weeks or a Friday-to-Saturday weekend. For those, Excel's NETWORKDAYS.INTL and WORKDAY.INTL take a weekend code, such as 11 for Sundays only.

NETWORKDAYS counts both the start and the end date, so it matches this calculator with “Count the start date too” ticked. WORKDAY leaves out the start date, like “Add business days.” Give either function the observed dates from the holiday table above as its holidays range and the results agree; leave the range out for weekdays only. Google Sheets has the same functions.

Shipping estimates such as “5–7 business days”

Enter the day the order ships (or the order date, if the estimate runs from the order) and add the business days. An order shipped on Wednesday, June 16, 2027 with a 5–7 business day estimate should arrive between Thursday, June 24, 2027 and Monday, June 28, 2027, because Juneteenth on Friday, June 18, 2027 is skipped. Carriers publish their own holiday schedules; if yours delivers on a federal holiday, untick the holiday box.

Contract and legal deadlines

Contracts, court rules and laws define business days themselves: which holidays count, whether the day of the event counts, and what happens when a deadline lands on a weekend. Some count calendar days instead and only move a deadline that lands on a weekend or holiday to the next business day; for those, add the days with the date calculator and step forward if needed. Check the rule that applies; this is a counting tool, not legal advice.

Projects, payroll and planning

To find the working days in a month, a quarter or a pay period, count from its first to its last day with “Count the start date too” ticked, as the month table above does. For a span in years, months and days use the date duration calculator; for sprint and planning weeks, the week number calculator.