Calligra Sheets DAYSINYEAR Function: Leap Years and Year Lengths

DAYSINYEAR returns the length of a particular Gregorian calendar year: 365 days in an ordinary year and 366 days in a leap year. This Calligra-specific guide follows the official KDE function handbook, matching XML function definitions, and the pinned Calligra 26.08.2 implementation. [K1–K3]

Target and evidence status: Calligra 26.08.2, released October 8, 2026, with particular relevance to the Qt 6 / KDE Frameworks 6 application commonly distributed on Linux. Official material was checked on 2026-10-12. Testing disclosure: numerical example outputs below are expected values independently checked with Gregorian-calendar calculations and/or traced to source code; they were not observed in Calligra Sheets. The installed release, workbook settings, conversions and export behavior still need live testing. [K1–K4]

=DAYSINYEAR(year)

The official documentation gives exactly one argument and no optional arguments or documented defaults. Implementation-registration nuance: unlike DAYSINMONTH, the pinned C++ registration does not call setParamCount(1) explicitly for DAYSINYEAR; we have not verified the default minimum/maximum argument range of the underlying registration class. Therefore the one-argument syntax is documentation confirmed, but statements about the native error for omission or extra arguments remain unverified until source-class or native execution checking. [K1, K2]

The C++ body converts the first argument to an integer year, calls QDate::isLeapYear(year), and returns 366 if true, otherwise 365. It does not construct a particular date or depend on the length of a selected month. Qt documents leap-year calculation in the Gregorian calendar. A long internal compatibility alternate identifier is registered (COM.SUN.STAR.SHEET.ADDIN.DATEFUNCTIONS.GETDAYSINYEAR); this is an alias rather than a separate function. [K2, K3, Q1]

Formula separators and locale: KDE’s English function handbook spells arguments with semicolons (;). Keep this syntax when following these Calligra examples; another installation or imported workbook may use a different delimiter. These date-counting functions return whole-number counts, which do not require locale-dependent date rendering, but cell types, date displays and parsing of text from external workbooks may still vary. Use numeric inputs rather than ambiguous quoted dates to reproduce the examples. [K1–K3]

Type Year into A1 and Days in year into B1. Enter the year integers in A2:A8. Enter =DAYSINYEAR(A2) into B2 and fill it down through B8. This is an independently calculated expected-output table, not a native spreadsheet test. [K1, K3, C1]

What the century rows teach: The Gregorian rule makes 1900 and 2100 ordinary 365-day years even though divisible by 4; 2000 and 2400 are leap 366-day years because divisible by 400. These independently checked arithmetic cases complement KDE’s documented DAYSINYEAR(2000) = 366. [K1, K3, Q1, C1]

1. Daily allocation of an annual amount. Enter the year in A2 and a nonnegative annual budget in C2, such as 36600. The formula:

=C2/DAYSINYEAR(A2)

For A2=2024 and C2=36600, expected 100 units per day. In 2025, the same annual total would give 36600/365 ≈ 100.2739726. This accounts for leap years rather than assuming every year has 365 days. Rates are mathematically calculated; accounting rounding rules vary by application. [K1, C1]

2. Count days remaining after a specified date. If A2=2024, B2=2, C2=29, use:

=DAYSINYEAR(A2)-DAYOFYEAR(A2;B2;C2)

The independently calculated expected result is 306 days after Feb 29 until the end of 2024. This formula measures days after that date; add 1 to include it. DAYOFYEAR is another registered Calligra function; the compound expression is not native tested. [K1–K3, C1]

3. Pull the year from a date cell. If E2 is a real date from =DATE(2000;6;15), the expected result of =DAYSINYEAR(YEAR(E2)) is 366. Excel or Sheets may use different list separators; Calligra’s handbook shows semicolons, and input-date parsing is locale-sensitive. [K1, K3, C1]

Unexpected year: Confirm A2 is numeric, not a two-digit code, text label or imported serial date. The year argument is an integer calendar year, not a date cell by itself. A date cell should first pass through YEAR(...). [K1, K3]

Noninteger or text input: The C++ implementation requests Calligra’s asInteger() conversion, but its exact handling of a value such as 2024.9 or text "2024" was not native tested; do not claim an error code or truncation without a separate verification. [K3]

Invalid or extreme years: QDate::isLeapYear(year) is a Boolean test and the code returns 365 on a false result. The source does not make an additional valid-date check in func_daysInYear, so an ordinary-looking 365 is not proof a bizarre input is a valid supported calendar date. Validate your year range upstream, especially with imported data. [K3, Q1]

Calligra 26.08.2 offers DAYSINYEAR directly, whereas Microsoft’s official Excel date/time function index instead exposes general DATE and YEAR tools. For positive Gregorian years within the supported date range and Excel’s usual comma separator, the corresponding annual day count can be calculated as: [M1]

=DATE(A2+1,1,1)-DATE(A2,1,1)

For A2=2024 the expected result is 366. Excel caveat: Excel’s 1900 date system incorrectly treats 1900 as a leap year. This alternative must not be used to validate the Calligra Gregorian result for 1900; use a modern supported year such as 2024. See Microsoft’s explanation, checked October 13, 2026. In Calligra’s handbook separator convention the comparable formula is =DATE(A2+1;1;1)-DATE(A2;1;1); however, imported date serial settings may differ, and the Excel-specific formula is not evidence for Calligra’s native function. Do not assume a custom DAYSINYEAR function or full alias string is portable into Excel, Google Sheets or other apps. [K1, M1, C1]

Is 1900 a leap year? No under the Gregorian calendar. While it divides evenly by 100, it does not divide evenly by 400, so the expected result is 365; 2000 returns 366. Do not use a divisibility-by-4-only formula. [Q1, C1]

Why did an imported date return an unexpected count? Confirm that the argument is the numeric year, not an entire serial date or text. If it is a true date use =DAYSINYEAR(YEAR(E2)) instead of passing E2 directly. Native parsing/coercion remains unverified. [K1, K3]

Why is there no default? The handbook documents one mandatory year. The source registration omits an explicit argument-count call, so its default validation behavior is pending native or class-source checking and must not be invented. [K1, K2]

What we verified, and what remains untested: The name/argument layout is official-documentation checked. The function’s C++ registration and calculation branch are source-code checked against one pinned Calligra revision. The examples are independently calculated expected results, not screenshots, automated tests or results copied from an executing Calligra instance. Evaluation of nonsensical text inputs, spreadsheet import coercions, large or negative years, overflows, plugin availability in a particular package, and exact error-display labels are not native-validated. Do not use this guide as a guarantee of behavior across every installed version. [K2, K3, Q1]

Use DATE to construct an actual date, DAY to extract a calendar day, MONTH to extract the month, YEAR for its year, and EOMONTH for a month-end date. These related functions perform distinct date operations. [K1]

• KDE Calligra Sheets official function reference — includes the DAYSINYEAR entry as well as its related date/time functions.
• KDE’s Calligra release listing — lists release 26.08.2 on 2026-10-08.
• Qt 6 QDate reference — documents the underlying Gregorian date methods cited below.
• Microsoft’s Excel date/time function reference — a separate product, relevant only to the explicitly labelled compatibility formulas.

The four external destinations above were checked for a current response when this manuscript was drafted on 2026-10-12. [K1, K4, Q1, M1]