About this tool
Work out how many business days sit between two dates when planning delivery windows, project timing, or response SLAs.
Business Days Calculator works in two modes. Count a range tells you how many working days fall between a start and end date, with separate switches for whether each endpoint is included. Add or subtract starts from one date and moves forward or backward by a number of business days to find a target date. Both modes use the weekend pattern you choose (Saturday/Sunday, Friday/Saturday, or Sunday only) and a list of holiday dates you paste in, one YYYY-MM-DD per line. The results panel goes beyond a single number: it breaks out weekend dates, holiday dates, holidays that landed on weekends anyway, duplicates, and supplied holidays outside the range, then lists the first 14 dates it evaluated so you can spot-check the logic.
- Counts business days in a bounded range with independent start and end inclusion rules.
- Adds or subtracts business days from a start date with an explicit start-count policy.
- Validates supplied holidays and exposes weekend overlaps, duplicates, and out-of-range dates.
How to use Business Days Calculator
Pick a mode with the Calculation mode toggle. For a range, enter Start date and End date (the span may run up to 3,660 calendar days) and decide whether Include start date and Include end date should be on. For a shift, enter Business days to shift (0 to 10,000), choose Add days or Subtract days, and turn on Count start date if eligible when the start day itself should be the first business day. Choose the Weekend pattern for the workweek, then paste holidays into the text area; up to 500 lines and 12,000 characters are accepted, duplicates are folded, and a bad line shows an error. The Load an example dropdown offers cases such as a Friday-Saturday workweek and a Korean holiday range. Results update as you type.
When this tool is useful
- A project manager converting 'ten business days after signature' in a contract into an actual calendar date.
- A customer support lead measuring whether a ticket was answered within a five-business-day SLA over a holiday week.
- An HR coordinator counting working days in a pay period for a team that follows a Friday-Saturday weekend.
- A logistics planner estimating a delivery date that must skip weekends and a list of national closures.
- A legal assistant checking a filing deadline where the start day is excluded and the deadline day is included.
Practical tips
- The tool never assumes a country's holidays; paste the exact dates your team observes or the count will be too high.
- In shift mode the start date is excluded by default, which matches most 'N business days from today' conventions; flip the switch if your policy differs.
- A holiday that falls on a weekend is listed under Holiday + weekend overlaps and is only removed once, so counts stay honest.
- Dates are calculated as plain UTC calendar days from 1900 to 2100, so daylight-saving changes never shift a result by a day.
- Settings are reflected in the page URL, which makes results shareable but also leaves the dates in browser history.
Examples you can test
Load an example, compare the result with the expected output, then replace it with your own input.
Count a month of workdays
Example input
Count a range, 2026-06-01 to 2026-06-30, Saturday/Sunday weekend, both endpoints included, holiday 2026-06-19
Expected output
21 business days: 30 calendar days minus 8 weekend dates minus 1 holiday
June 2026 starts on a Monday, so the eight weekend dates are four Saturdays and four Sundays.
Add 20 business days
Example input
Add or subtract, start 2026-03-09, 20 days, Add days, start not counted, holiday 2026-03-17
Expected output
Target date 2026-04-07, with 8 weekend dates and 1 holiday skipped along the way
This is the built-in 'Add 20 business days' example, so you can load it and compare the evaluated dates list.
Validation checklist
- Confirm the weekend pattern matches the workweek of the team or jurisdiction involved.
- Paste every observed holiday in YYYY-MM-DD form and check the duplicate and out-of-range counts.
- Decide deliberately whether the start and end dates should count.
- Scan the first 14 evaluated dates to confirm the first skipped weekend looks right.
- Recheck ranges that cross a year boundary or include February 29.