Business Days Calculator
Count business days between dates.
Input
Result
What is a Business Days Calculator?
A Business Days Calculator counts the number of weekdays (Monday through Friday) between two dates, excluding weekends and optionally excluding holidays. You enter a start date and an end date, and the calculator returns the total business days, along with the number of weekends and holidays excluded. Project managers, HR professionals, contractors, and anyone planning work timelines use business days calculators to estimate delivery dates, calculate shipping times, determine contract deadlines, and plan project schedules that only count working days. Unlike a regular day counter that counts all calendar days including weekends, this tool focuses on the days when businesses and offices typically operate.
How to calculate business days manually (the formula)
To count business days manually between two dates: count the total number of days, subtract the weekends, and subtract any holidays. For weekends, every 7-day period has 2 weekend days, so total weekends ≈ floor(TotalDays / 7) × 2, plus any extra weekend days in the remainder. The formula is: Business Days = Total Calendar Days − Weekend Days − Holiday Days. For example, from Monday to the following Monday is 7 calendar days, which has 2 weekend days, giving 5 business days. For a more precise count, you can also use the formula: Business Days = (TotalWeeks × 5) + WeekdayRemainder − Holidays, where the total weeks is the number of full weeks between the dates.
Example calculation
Suppose you want to count business days from January 1, 2025 (Wednesday) to January 15, 2025 (Wednesday). Total calendar days = 14. January 1 is a Wednesday. Counting forward: Jan 1 (Wed), Jan 2 (Thu), Jan 3 (Fri), Jan 4 (Sat), Jan 5 (Sun), Jan 6 (Mon), Jan 7 (Tue), Jan 8 (Wed), Jan 9 (Thu), Jan 10 (Fri), Jan 11 (Sat), Jan 12 (Sun), Jan 13 (Mon), Jan 14 (Tue), Jan 15 (Wed). That is 14 days. Weekends are Jan 4, 5, 11, 12 = 4 weekend days. Calendar 14 − 4 = 10 weekdays. If New Year's Day (Jan 1) is a holiday, subtract 1 more = 9 business days. The calculator handles all of this automatically, including custom holiday lists.
Common mistakes
- Assuming every week has exactly 5 business days — A week that starts on Thursday and ends the following Wednesday only has 4 business days if it includes a weekend.
- Forgetting to account for public holidays — Business days exclude holidays like Christmas, New Year's, and Thanksgiving. Forgetting them overestimates business day counts.
- Confusing business days with working days — Some businesses operate on Saturdays (6-day work week). Business days usually mean Monday through Friday only.
- Off-by-one errors in date ranges — Counting business days from Monday to Tuesday is 2 business days if both are included, but only 1 if you exclude the start date.
- Not accounting for regional holiday differences — A holiday in the US (July 4) is a regular business day in the UK. Use the correct holiday calendar for your region.
Frequently asked questions
How do I count business days between two dates?
Enter a start date and an end date. The calculator counts all weekdays (Monday to Friday) between them, excluding weekends. Optionally, you can exclude specific holidays.
What counts as a business day?
A business day is any weekday that is not a weekend (Saturday or Sunday) and not a public holiday. Monday through Friday are typically business days, depending on the holiday calendar.
How do I exclude holidays from the count?
You can add specific dates as holidays. The calculator will skip those dates in addition to weekends when counting business days.
What's the difference between calendar days and business days?
Calendar days include every day of the week (Saturday, Sunday, and holidays). Business days count only Monday through Friday, excluding holidays. 10 calendar days is about 7 business days.
How many business days are in a year?
A standard year has about 260 business days (52 weeks x 5 days), minus any public holidays. This varies by country and year.
Can I add business days to a date?
Yes, enter a start date and the number of business days to add. The calculator finds the date that many business days later, skipping weekends and holidays.