Working Days Calculator

Deadline management, invoice terms, and HR payroll windows all run on working days, not calendar days. A “10-business-day” turnaround that starts on a Wednesday arrives on the following Monday, not ten days later on a Saturday. Working Days Calculator does that arithmetic correctly, skipping every weekend and any public holidays you provide, so you get the right count without building a mental calendar.

Pick your work week model. The standard Mon–Fri mode handles most payroll and legal deadlines. Switch to Mon–Sat if your industry uses a 6-day week. Paste your country’s public holidays into the holidays box and they are excluded automatically, so a holiday that falls on a Tuesday does not inflate the count.

Worked Example: a Project Sprint

Press Load Sample and the tool loads 2026-10-19 to 2026-11-14 — a Mon–Sat window that crosses four weekends. Under the default Mon–Fri mode the result is 19 working days, drawn from 27 calendar days minus 8 weekend days and 0 holidays. Switch to Mon–Sat and the count rises to 23, because every Saturday becomes a workday.

To block out Thanksgiving (2026-11-26): type it into the holidays box and the count drops by one. Adding Christmas (2026-12-25) as a second line drops it again. Each valid date is confirmed by the “N holidays loaded” note under the textarea.

The Method: How Each Day Is Counted

The counter walks the date range one day at a time in UTC, testing each day in turn: weekend? skip. Holiday set member? skip. Otherwise, add 1 to the working total. Both the start and end dates count as working days (inclusive on both ends), which matches how employment contracts and court deadlines phrase their rules.

The Add Working Days helper works in the same UTC frame: starting from the Start Date, it advances one calendar day at a time and counts only non-weekend, non-holiday days until N are accumulated. This means “add 10 working days from Mon 19 Oct” lands on Fri 30 Oct (two weekends skipped), not 10 calendar days later on Wed 29 Oct.

Edge Cases and Valid Inputs

• Same start and end date: if that day is a weekday and not a holiday, the result is 1 working day, not 0.
• Start date after end date: the tool shows “Start date must be on or before end date.” and hides the result until the range is valid.
• Holiday dates outside the range are silently ignored — they parse and count towards the “N holidays loaded” total but never subtract from the result.
• Invalid calendar dates like 2026-02-30 or a non-YYYY-MM-DD line in the holidays box are skipped. The textarea accepts # comment lines so you can label each holiday with its name.
• Working Days to Add is capped at 9,999 to keep the forward-count helper responsive; that covers roughly 40 years of workdays.