Irish Calculators
Work & pay

Length of Service Calculator: Years and Days

Measure service between your start date and an as-of date, with a calendar breakdown and total days. Enter documented exclusions separately; the result does not establish pension or redundancy entitlement.

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Your numbers

days
Your figures stay on this device.

How the calculation works

Length of service is shown in two ways: elapsed calendar years, months and days, and a separate counted-day total after documented exclusions. These outputs answer different questions and are deliberately not collapsed into an assumed employment entitlement.

Elapsed days are the UTC calendar-date difference, excluding the start date. Counted days subtract documented exclusions. Calendar years/months are counted by anniversaries with month-end clamping.

  1. Measure elapsed calendar days

    The dates are compared at UTC midnight. This avoids daylight-saving changes adding or removing fractions of a day from a date-only service record.

  2. Build the calendar breakdown

    Count complete monthly anniversaries, clamping an anniversary to the end of a shorter month where necessary. Split those months into years and remaining months, then count residual days.

  3. Apply documented exclusions separately

    Subtract excluded days from total elapsed days. The calendar years-and-months description still spans the original dates and therefore still includes any gaps.

Worked example: One year

Sample inputs demonstrate the method. They are not a forecast or product offer.

The first example runs from 1 January 2025 to 1 January 2026 with no exclusions. Those dates are 365 elapsed days apart, so counted service is 365 days and the calendar duration is one year.

Service start date
2025-01-01
As-of date
2026-01-01
Documented excluded service (days)
0

Expected result

Counted service days
365
Worked example: Leap year and exclusion

Sample inputs demonstrate the method. They are not a forecast or product offer.

Service start date
2024-01-01
As-of date
2025-01-01
Documented excluded service (days)
6

Expected result

Counted service days
360

Understanding your result

Counted service days are useful when you already know which days should be excluded. The calculator does not decide whether a break in employment or leave should count under a particular rule.

The calendar breakdown is not produced by dividing days by 365 or 30. Calendar months and leap years vary, so those shortcuts can disagree with anniversary-based duration.

Questions you might have

What does this length of service calculator include?

Measure elapsed calendar service between two dates, with a separate day total after any documented excluded service.

Which assumptions should I check?

Calendar duration is not an automatic pension, redundancy or employment-right entitlement. The calendar breakdown includes gaps; excluded days affect only the separate counted-days result.

Choosing the right inputs

Service start date
Use the recorded start date, with no time of day. The elapsed-day convention excludes this starting date.
As-of date
Enter an as-of date on or after the start. Real calendar dates from 1900 to 2200 are supported, with leap days counted when present.
Documented excluded service
Enter a whole number of documented excluded days, no greater than elapsed days. This reduces counted service days only, not the calendar-duration breakdown.

Common mistakes to avoid

  • Do not read the unadjusted calendar duration as though excluded service had been removed from it.
  • An elapsed duration does not by itself establish redundancy, pension or other employment-right entitlement.

Assumptions to check

  • Calendar duration is not an automatic pension, redundancy or employment-right entitlement. The calendar breakdown includes gaps; excluded days affect only the separate counted-days result.

Sources and method

Read our calculation and testing approach.