Calculator
Employment seniority calculator
The calculator measures one continuous period using calendar years, months and days and can add full years already recognised by the user or employer.
Calculator
Enter data
The start and end dates plus any previously recognised full years. Fields marked with an asterisk are required.
How to use the calculator
- Enter the first and final day of the period.
- Add only full years that have already been recognised.
- Review the duration and verify which periods legally qualify.
Calculation details
Formula and calculation method
The period includes both entered dates and is expressed as calendar years, months and days. Recognised full years are added separately.
Worked example
A period from the first day of one month through the final day of that month includes the final day and produces one complete calendar month.
Limitations
- This version does not resolve overlapping periods or decide whether a contract, education or business activity legally qualifies.
Sources
Engine version: 1.0 · Last reviewed: 3 August 2026
Frequently asked questions
Does a civil-law contract count towards seniority?
Polish rules changed in 2026. Confirm the effective date and required evidence for your employer.
Can overlapping periods be added together?
They should not be double-counted. This version calculates one continuous period.