Quick answer
Project plans often say something takes 5, 10, or 20 business days. This page helps translate that into a real calendar date after weekends and holidays.
Why project dates slip
A task estimated at ten business days does not finish in ten calendar days if it crosses weekends or holidays. That is a common cause of unrealistic delivery dates.
Planning checks
Agree whether the start day counts, whether public holidays are excluded, and whether the estimate assumes full business days or partial days. Then use the calculator to create a realistic date.
Before committing the date
Check whether the estimate assumes uninterrupted working days, whether dependencies can start immediately, and whether public holidays should be excluded from the plan.
Download the 2026 working days calendar
Get a free 2026 working days calendar for the United Kingdom, Ireland, and United States. The Excel file includes monthly summaries, daily working-day flags, and public holiday sheets.
Use the free calculator
Open the main calculator, choose your start and end dates, select the country, and decide whether public holidays should be excluded.
FAQs
How long is 10 business days?
Usually about two calendar weeks, longer if holidays are excluded.
Should project plans use business days?
Business days are often clearer for operational work because they skip weekends.
Can I use this for delivery estimates?
Yes, as a planning aid, especially when the promise is expressed in working days.