Date & Business Days Calculator
Add or subtract calendar or business days from a date, and count days — including working days — between two dates.
How to use this tool
- To project a deadline: pick a start date, choose add or subtract, enter the number of days, and pick calendar or business days.
- To count between dates: enter both dates and read the calendar-day and business-day counts.
How it works
Business-day mode steps over your selected weekend days (Sat–Sun by default, or Fri–Sat / Sun-only schedules) and, when enabled, the 11 US federal holidays on their observed dates — a Saturday holiday is observed the preceding Friday and a Sunday holiday the following Monday, per 5 U.S.C. 6103. Month and year math clamps to month-end, so Jan 31 + 1 month = Feb 28 (or 29 in a leap year).
Frequently asked questions
What counts as a business day?
Any day that isn't in your selected weekend and, when the holiday option is on, isn't a US federal holiday (observed date). State holidays and employer closures aren't included — adjust for those by hand.
Which holidays are skipped?
The 11 US federal holidays: New Year's Day, MLK Jr. Day, Washington's Birthday, Memorial Day, Juneteenth, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving, and Christmas — on their observed dates when they fall on a weekend.
What's 10 business days from today?
Two calendar weeks if no holidays intervene — but let the tool do it: weekends make manual counting error-prone, which is why '10 business days' and '14 days' usually coincide but not always.
Is the end date included when counting between dates?
The count is the days you'd step through moving from the first date to the second — the start date is excluded, the end date included. Monday to Friday is 4 days.