Workdays (Business Days) Calculator

Count business days between dates and add/subtract workdays. Private by design—everything runs locally in your browser.

1) Workdays Between Two Dates

Paste dates in YYYY-MM-DD format, one per line. Invalid lines are ignored.

2) Add / Subtract Workdays

About This Workdays Calculator

Workday math can be surprisingly tricky when weekends and holidays get in the way. This Workdays Calculator helps you count business days between two dates and add or subtract workdays from a starting date, all in a few clicks. It is ideal for planning timelines, estimating delivery windows, and setting realistic due dates without manual counting.

A workday usually means Monday through Friday, but schedules vary by region and industry. This calculator lets you choose which days are considered working days and which are weekends. You can also paste a list of custom holiday dates to exclude them from the count, making the result closer to your actual business calendar.

How it works is simple: it steps through the calendar day by day, skipping any dates that are marked as non-working, and counts only the days that match your settings. For accuracy, calculations run at midnight UTC to avoid daylight saving time shifts that can cause off-by-one errors in some date tools.

How to use it step by step

  1. Choose whether you want to count workdays between two dates or add/subtract workdays from a base date.
  2. Enter your start date and end date, or a start date with a workday offset.
  3. Select which weekdays count as workdays for your schedule.
  4. Paste any holiday dates you need to exclude.
  5. Click Calculate to see the result immediately.

Real-world uses include estimating project deadlines, calculating response times for support tickets, scheduling payroll or invoicing cycles, and planning shipping or delivery windows. For example, if a client asks for a proposal in seven business days, this tool will tell you the exact date, skipping weekends and holidays that would otherwise push the deadline.

Results are shown in ISO format (YYYY-MM-DD) so they can be copied into spreadsheets, emails, or project tools without confusion. Everything runs locally in your browser for privacy, and your holiday list is handled on your device only.

Tip: use the Set Today shortcut to prefill date fields with today’s UTC date.

Workdays Calculator: FAQs

How are workdays determined?

By default, workdays are Monday–Friday. You can choose to treat Saturday and/or Sunday as workdays with the toggles.

What about holidays?

Paste holiday dates (one per line) and they’ll be excluded when counting or adding workdays. No data leaves your device.

Is the counting inclusive?

You can choose Inclusive (count both start and end) or Exclusive (exclude start). For adding/subtracting, the base date isn’t counted unless you land on it.

Does it handle leap years?

Yes. All calculations are UTC-based and correctly handle leap years.

5 Fun Facts about Workdays

53-week years happen

ISO calendars occasionally pack in 53 numbered weeks (like 2020 and 2026), which can shift planning sprints by a whole week.

Calendar oddity

Friday–Saturday weekends exist

Not everyone stops on Saturday–Sunday: some regions take Friday–Saturday weekends, changing what “5 workdays” means.

Global schedules

4-day weeks are spreading

Pilot programs in the UK, Iceland, and New Zealand ran 4-day workweeks with no pay cuts—most participants kept or increased output.

Future of work

Holidays can erase a whole week

Stack a midweek holiday next to a weekend and a company shutdown, and you can drop below 60% of normal workdays for that week.

Planning pitfall

Markets love 252

U.S. stock exchanges average about 252 trading days a year—handy for quick returns math like CAGR and volatility.

Finance trivia

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