Calligra Sheets MONTH Function: Month Numbers and Reporting

The MONTH function extracts the calendar month as 1 through 12, regardless of the language of any displayed month label. For a leap-day date, =MONTH(DATE(2024;2;29)) has an expected result of 2. MONTH and the separate MONTHS/MONTHNAME functions are not interchangeable.

Applies to: the function registry and implementations from Calligra Sheets 26.08.2, released October 8, 2026, examined October 12, 2026. KDE’s current application listing supports Linux via distribution packages/Flatpak; this guide does not claim that every version/platform executes identically. Results marked expected below were calculated independently or inferred from source. Calligra Sheets was not installed or run to observe them.

=MONTH(date)

• date (required, exactly one argument): an actual date value, an applicable cell reference containing a date, or an expression evaluated as a date. The published function XML describes the parameter as a String/Text, while the pinned implementation immediately converts it through ValueConverter::asDate before extracting its calendar component. Date strings are locale sensitive; an authentic date value is safest. Argument order is simply the one date to examine; there are no optional parameters or default values in the pinned registration.
• Return: a whole number from 1 to 12. The code uses Qt QDate and returns a numeric Value rather than a formatted date string. Choose a General/Number display format for result cells so the integer is visible.
• Example: =MONTH(DATE(2024;2;29)) → expected 2. The nested DATE call uses three required integer arguments in year, month, day order.

Important KDE documentation/source discrepancy

The older official KDE handbook entry says that leaving out date gives the current month number. The pinned Calligra 26.08.2 source does not register a zero-argument overload. It registers MONTH without calling setParamCount, while Function.cpp defaults to one mandatory argument and its execution-time validation rejects zero with a VALUE-class error. Thus =MONTH() should not be recommended; its exact cell-visible error spelling has not been observed in a native application. To extract a value from the current date, the proposed alternative is:

=MONTH(TODAY())

Here the result changes with the real date and recalculation settings. Unlike =MONTH(), it supplies a date value; native execution remains untested.

Language, locale and typing

The official KDE handbook shows semicolon-separated multiargument functions, for example DATE(2024;2;29). Localized spreadsheets may use different decimal notation and input conventions: follow the installed Insert Function guidance and use the locale-appropriate separator if necessary. "2/22/2002" appears as a text-date example in KDE’s documentation, but parsing an ambiguous quoted date is not guaranteed across locale or platform. For reproducible examples, construct date cells using DATE, or import real date values and inspect their type.

Enter A1 as Input date and B1 as MONTH result. In A2:A5 enter the date-creating formulas exactly as shown. These formulas produce the display dates in an appropriate ISO-style date format; adjust the display formatting only, not the underlying date values.

Then type =MONTH(A2) into B2 and fill it through B5, letting the relative reference change to A3/A4/A5. The final column contains independently calculated expected values, not software-observed output.

Why this works: each input is an unambiguous date created from its year, month and day; the func_month implementation converts to a date, checks for conversion errors, and extracts QDate::month(). The four dates were cross-checked with an independent Gregorian calendar calculation.

If A2:A5 contains the worked-example dates, enter the following formula in C2 and fill it through C5:

=INT((MONTH(A2)-1)/3)+1

The quarter is the calendar quarter, not a company’s custom fiscal year. The expected values, independently computed from the recorded dates, are:

The formula is a transparent combination of MONTH, integer division and arithmetic. These results are expected, not observed in a running application. Verify that INT and the document’s settings behave as required before production use.

Another application: flag a reporting month

=IF(MONTH(A2)=10;"October reporting";"Other month")

For A2 (February 29, 2024), the expected text is Other month; for A5 (October 12, 2026) it is October reporting. Change 10 to the month number you want to review. This formula does not distinguish different years’ October entries; combine MONTH with YEAR if the reporting period needs a year too.

• Months are numbers, not labels: MONTH returns 2, not "February". The separately registered MONTHNAME function is intended for labels; its locale behavior requires native checking.

• Avoid month-day ambiguity: "04/05/2025" can mean April 5 or May 4 depending on the input locale. Use =DATE(2025;4;5) instead for a known April 5.

• Unexpected zero-argument behavior: the handbook says the present month is used if the argument is missing, but the pinned source rejects the zero-argument form. Use =MONTH(TODAY()) instead (current date is dynamic, and native execution is not verified).

• DATE with zero month or day: pinned DATE explicitly returns a VALUE-class error for a month or day of 0. A formula such as MONTH(DATE(2024;0;1)) is not a portable month-wrap approach.

• Wrong argument count: zero parameters or two parameters do not match the one-argument registration. The engine checks argument count and returns a VALUE-class error at source level. Confirm the rendered error text in the version actually installed.

• Non-date or invalid reference: the function first calls asDate, and returns its error result when conversion fails. The precise accepted date text, serial/date-base interpretation, and display/error behavior need native validation.

• The answer looks like a date instead of a number: change the output cell format to General or Number; cell formatting does not change the semantic meaning of MONTH.

• Examples use the wrong calendar convention: use DATE(year;month;day) rather than ambiguous slash-separated strings, and check that the imported data represents local dates rather than unparsed text.

• Runtime/portability limits: the source inspection establishes 26.08.2 logic and function registration; it does not establish every operating-system binary, plugin build, number format, timezone interaction, or spreadsheet application’s edge-case result.

Excel uses MONTH(serial_number) and returns 1–12, with an expressly required date argument. The logical extraction matches Calligra’s documented purpose, but serial-number epochs, imported strings and localized date/argument conventions may differ. Excel guidance recommends constructing date values with DATE rather than entering ambiguous text. Microsoft’s official Excel MONTH documentation was independently checked October 12, 2026. This comparison refers only to the expressly documented shared purpose; no Excel result is used as proof of Calligra runtime behavior. MONTH has no explicit alternate registered name in the pinned Calligra catalogue.

KDE separately registers DATE to construct a date; TODAY to provide the current date; and the other component functions DAY, MONTH, YEAR. These are related functions, not aliases. See the official source links below.

• Official KDE MONTH handbook entry — syntax, one date parameter, date-text examples and the contradictory optional-argument claim; accessed 2026-10-12.
• Pinned Calligra 26.08.2 datetime.cpp function registration and implementation — source-checked MONTH arity, date conversion, error propagation and extraction; checked 2026-10-12.
• Pinned datetime.xml description — documented argument and return types, syntax and examples; checked 2026-10-12.
• Default minimum/maximum function argument count and arity guard — explains the contradiction with the handbook’s no-argument claim; checked 2026-10-12.
• Pinned DATE constructor and month/day zero guard — supports reproducible date values and the zero-input caveat; checked 2026-10-12.
• KDE Calligra Sheets releases — latest listed stable release 26.08.2 (2026-10-08) as checked 2026-10-12.
• Microsoft Excel MONTH reference — comparison only; checked 2026-10-12.

Testing limitation: Examples are independently calculated expectations. Native locale, date conversion and visible error behavior remain untested.