Irish Calculators
Work & pay

Notice Period End Date Calculator

Enter the notice start and the period specified in your contract to find its calendar endpoint. The tool applies your chosen date convention rather than deciding how much notice is legally owed.

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Your numbers

Your figures stay on this device.

How the calculation works

The notice-period tool performs calendar arithmetic after you have established the relevant start, period and endpoint convention. It can express a period in days, weeks or calendar months, but does not determine when notice is legally served or how much is owed.

Add calendar days, weeks or calendar months to the specified start. Month addition clamps to the last day when the target month is shorter. Optionally subtract one day for an inclusive final-day convention. A zero-length period returns the start date under either convention.

  1. Add the chosen period

    Days move by calendar days and weeks by seven calendar days. Month mode moves by calendar months rather than assuming a fixed number of days.

  2. Handle a shorter target month

    If the starting day does not exist in the target month, the date is clamped to that month’s last day. Leap-year February is handled by the actual calendar.

  3. Apply the endpoint convention

    For a positive period, the previous-day option subtracts one day from the anniversary. A zero-length period returns the original date under either option.

Worked example: Month-end clamp

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

The first example starts on 31 January 2026 and adds one calendar month using the anniversary convention. February 2026 has no 31st day, so the endpoint is clamped to 28 February 2026.

Notice period start date
2026-01-31
Period length
1
Period unit
Calendar months
End-date convention
Anniversary date

Expected result

Calculated period endpoint
2026-02-28
Worked example: Four weeks

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

Notice period start date
2026-10-01
Period length
4
Period unit
Calendar weeks
End-date convention
Anniversary date

Expected result

Calculated period endpoint
2026-10-29

Understanding your result

The resulting endpoint follows the inputs exactly. It does not skip weekends, holidays or workplace closures, because this is a calendar-period tool rather than a business-day counter.

Where a contract or procedure specifies another counting rule, use that rule to choose the appropriate inputs or a different tool. The displayed date does not resolve that interpretation.

Questions you might have

What does this notice period date calculator include?

Find the calendar endpoint of a notice period using the period and date convention specified in your contract.

Which assumptions should I check?

The tool does not decide when notice was legally served, how much notice is owed, or whether a contract requires a different final day. Confirm the start date and convention first.

Choosing the right inputs

Notice period start date
Enter the date from which the agreed period is to be measured. Delivery, receipt and contractual commencement can be different events; resolve the applicable start separately.
Period length
Use a non-negative whole number of the selected unit. The engine accepts up to 1,200 units, provided the resulting date remains within its supported calendar.
End-date convention
Choose the anniversary date or the day before it. This is an explicit convention, not an automatic legal interpretation of an inclusive final day.

Common mistakes to avoid

  • Do not replace one calendar month with thirty days and expect every result to match.
  • An already-adjusted final date should not be entered as the start and adjusted a second time.

Assumptions to check

  • The tool does not decide when notice was legally served, how much notice is owed, or whether a contract requires a different final day. Confirm the start date and convention first.

Sources and method

Read our calculation and testing approach.