Workday Calculator

Workday calculator for deadline dates and business-day planning

A workday calculator helps you find the calendar date that lands a specific number of workdays away from a start date. This is useful when a promise, service-level agreement, or internal task is defined in business days rather than calendar days. Instead of guessing and then correcting for weekends, you can calculate the deadline in one step and understand how many days were skipped.

This calculator is designed for a simple, common decision: “If I start on this date, what date is N workdays later (or earlier)?” It excludes weekends (Saturday and Sunday) automatically. If you want to tighten the result for real-world planning, you can optionally exclude public holidays by entering a list of dates. That keeps the tool practical without forcing you to look up a full holiday calendar when you do not need it.

To use it, enter your start date in YYYY-MM-DD format and enter how many workdays you need to add. If you are counting backwards from a due date to find a start date, switch the direction to subtract workdays. The result shows the target date and a small breakdown so you can see the impact of weekends and holidays. If the answer looks off, the fastest fix is usually to confirm the start date format and whether you meant to count the start day as day 1.

Assumptions and how to use this calculator

• Workdays are Monday through Friday. Saturday and Sunday are treated as non-working days.
• The start date must be a real calendar date in YYYY-MM-DD format (for example 2025-12-22).
• The workday count is a whole number. Decimals are not meaningful for most deadline definitions.
• If “Count the start date as workday 1” is enabled, the start date is only counted when it falls on a workday.
• Holiday exclusion only applies to the dates you provide. If you do not supply a date list, the calculator will not assume any holiday calendar.

Common questions

What is the difference between workdays and calendar days?

Calendar days count every day in a row. Workdays skip non-working days (typically weekends). Ten calendar days after a Monday is always a Thursday, but ten workdays after a Monday usually lands later because weekends are skipped.

Should I count the start date as day 1?

It depends on how the deadline is defined. Many business processes treat the next workday as day 1, especially if work starts after the beginning of the day. If your instruction says “within 5 workdays of receipt,” you usually do not count the receipt day unless it is explicitly stated. Use the advanced option to match your specific rule.

What happens if my start date is on a weekend?

Weekends are not counted as workdays. If you are not counting the start date, the calculator will move forward (or backward) until it reaches the next workday and then begin counting. If you enable counting the start date as day 1, a weekend start date still will not count as day 1.

How do I handle public holidays accurately?

If your deadline is sensitive to holidays, enable holiday exclusion and paste the holiday dates you care about as YYYY-MM-DD values separated by commas. Only those dates will be excluded. This is intentional: it avoids wrong results caused by assuming the wrong country or region.

Why does my result differ from another workday calculator?

Differences almost always come from definitions: whether the start day counts, what the weekend days are, and which holidays are excluded. If another tool uses a built-in holiday calendar or a different weekend pattern, it will produce a different date even with the same start date and workday count.