werktage rechner

What is a Werktage Rechner?

A Werktage Rechner is a workday calculator used to count the number of valid working days between two calendar dates. This is useful for project planning, payroll processing, notice periods, delivery promises, and vacation calculations.

In German-speaking contexts, people often distinguish between:

• Kalendertage (calendar days)
• Werktage (workdays, often Monday to Saturday)
• Arbeitstage (working days, often Monday to Friday)

Because legal and business definitions can vary by contract and region, this tool lets you choose between a 5-day and 6-day working week and optionally remove custom holidays.

How this calculator works

1) Date range

You choose a start date and an end date. The calculator then checks each day in the range.

2) Workweek model

Select either:

• 5-day model: Monday to Friday count as workdays.
• 6-day model: Monday to Saturday count as workdays.

3) End-date inclusion

If enabled, the end date is included in the calculation. If disabled, the range ends one day earlier.

4) Holiday subtraction

Any custom holiday entered in the list is removed only if it falls on a counted workday. This prevents double subtraction for weekends.

Common use cases

• HR and payroll: Determine paid working days in partial months.
• Freelance contracts: Estimate billable days between kickoff and deadline.
• Operations: Calculate lead times excluding weekends and holidays.
• Personal planning: Track time until vacation or important milestones.

Best practices for accurate results

Use the correct definition

Always align the calculator setting with your contract or policy. Some organizations treat Saturday as a regular workday; others do not.

Keep a holiday list ready

For recurring planning, maintain a yearly holiday list in YYYY-MM-DD format. You can paste it directly into this tool.

Document assumptions

When sharing timelines, include assumptions such as workweek type, local holidays, and whether the final day is counted.

Example scenario

Suppose a project runs from 2026-03-01 to 2026-03-31 with a 5-day week. If you add one holiday on 2026-03-20, the calculator reports:

• Total calendar days in range
• Potential workdays before holidays
• Number of holidays that overlap workdays
• Final workdays after subtraction

This gives a clearer timeline for staffing and client communication than calendar days alone.

Final thoughts

A reliable workday count is a small detail that has a big impact. Whether you call it a Werktage Rechner, Arbeitstage Rechner, or business day calculator, the key is consistency: use one method, apply it everywhere, and communicate it clearly.