EASTERSUNDAY Function (Gnumeric)

• Introduced: Gnumeric 1.9.15. The official 1.9.14-to-1.9.15 source diff adds the Christian-date implementation and registers all five named functions; the release notes identify the new calendar group. No exact release day is inferred from an archive timestamp.
• Documented support: Registered in the Christian Date Functions plugin for Gnumeric 1.12.62. No retirement is established.
• Last functioning version: Unverified; source support does not prove application execution.
• Evidence dates: The 1.12.62 source snapshot was retained October 13–14, 2026. The historical release diff and notes were retrieved October 15; calculations and this full guide were reviewed that day. No native Gnumeric or GUI test was run.

EASTERSUNDAY returns the Gregorian Easter Sunday used by the Roman-rite calendar described in the Gnumeric help. It returns a worksheet date serial, not the text name of a holiday. It is not an Orthodox/Julian Easter calculator and does not determine whether an employer, school or jurisdiction closes on that date.

=EASTERSUNDAY([year])

The single numeric year argument is optional. With an explicit year, the shared helper converts it to an integer and applies Gnumeric’s year adjustment: 0–29 become 2000–2029, while 30–99 become 1930–1999. Thus 29 and 30 differ by nearly a century, not by one year. Use four-digit years for an auditable calendar. Negative integer years and years above 9956 return #NUM!.

The help states a nominal lower bound of 1582, but actual acceptance depends on date conventions and whether negative dates are enabled. The year-adjustment helper can reject years before the workbook’s 1900 or 1904 base. The modern worked years avoid this setting-dependent region. Blank and text coercions are unverified; an omitted argument is a deliberate separate operation.

Create EasterYears with Year in A1 and Easter in B1. Enter 2024, 2025, 2026, 2027 and 2028 in A2:A6. Put =EASTERSUNDAY(A2) in B2 and fill through B6. The expected dates are March 31, 2024; April 20, 2025; April 5, 2026; March 28, 2027; and April 16, 2028. Display B as dates rather than leaving the underlying serial numbers unexplained. In C2 enter =B2=DATE(2024,3,31) as a one-row explicit control; its expected result is TRUE.

These ISO dates make the expected calendar result unambiguous. A workbook can display a different localized date format without changing the underlying date. The table does not specify a date-system-dependent serial number.

Build a reproducible event-offset sheet instead of typing this year’s holiday once and reusing it forever. Put 2026 in B2, =EASTERSUNDAY(B2) in B3, =B3-14 in B4 and =B3+7 in B5. These dates are April 5, March 22 and April 12, 2026. They can represent an arbitrary two-week preparation date and a one-week follow-up date; those labels are your scheduling choices, not additional religious rules supplied by EASTERSUNDAY.

On a copy, change B2 to 2027. B3 becomes March 28, B4 March 14 and B5 April 4. The differences B3-B4 and B5-B3 stay 14 and 7. If the dates fail to move with the year, inspect whether the holiday cell was replaced by a fixed date or whether a copied formula still points to a different year. The difference between Easter 2026 and Easter 2027 is 357 days, so adding a fixed 365 days is not an annual Easter calculation.

The no-year helper reads the current system time, derives the calendar year and computes this specific holiday. It advances to next year only when this year’s holiday is strictly before the date being evaluated. Therefore the current holiday date itself is included in “next”; it does not automatically skip to next year on that day.

For a hypothetical evaluation date of 2026-04-04, =EASTERSUNDAY() has reference date 2026-04-05. On 2026-04-05, it still has that date. On 2026-04-06, it changes to 2027-03-28. These are simulated clock inputs to the source rule, not observations of today’s application output. The functions are registered as volatile; actual recalculation timing, timezone handling and saved-workbook caching were not tested.

For an annual schedule, pass the year explicitly. The no-argument form means the next occurrence relative to the clock when evaluated, rather than the holiday for whatever year appears in a neighboring heading. After Easter has passed, an unchanged heading could therefore label a next-year result incorrectly. A date format controls display; it does not select the calendar algorithm.

If the output looks like an integer, inspect the cell’s date format before changing the formula. If a year is rejected, inspect the four-digit input and the workbook’s date conventions. Do not repair an unsupported date by silently changing the requested year. The shared implementation includes a correction for negative offsets crossing the fictitious February 29, 1900 serial-date gap; the simple date-offset worksheet identities above are claimed for the stated modern years, not every historical serial boundary.

Check exact function spelling and the Christian Date Functions plugin when resolving availability issues. This guide does not supply a tested plugin-installation workflow. Error displays for malformed expressions, locale-specific entry, external workbook import and extreme serial values are unverified. The explicit-year controls and hypothetical-clock controls serve different purposes and should be kept separate.

• Function-specific help
• Worksheet callback and exact calendar offset
• Shared Easter algorithm and serial conversion
• Gnumeric official function catalogue

ASHWEDNESDAY, GOODFRIDAY, DATE.