MONTHS Function (Calligra Sheets)

• Introduced: First release not established; the name is present in Calligra 2.4.0 source.
• Supported in: Calligra Sheets 26.08.2, with the limitations described here; no retirement established.
• Scope: Desktop Sheets with the Date & Time module. Formulas use English names and semicolon separators.
• Checked: October 14, 2026: selected 25.04.2 engine-library formulas and independent calendar/time reconstructions; 26.08.2 source only. The test locale was C, with Monday as its week start. No GUI-cell or import execution is claimed.

MONTHS returns an integer using one of two calendar algorithms. Mode 0 starts with the difference in year/month coordinates and can subtract one when the ending day is earlier. Mode 1 counts between an advanced starting month and the ending month. The examples make the endpoint rules explicit. Official function reference.

=MONTHS(start_date;end_date;type)

start_date, end_date and type are all required. Type 0 selects the day-sensitive count. Any nonzero converted integer selects the other branch; the documented choice is 1. Fractional type values use the converter’s floor operation, so .9 selects 0 and 1.9 selects 1. Registration and implementation.

Numeric results are rounded here to twelve decimal places. The reconstruction column applies independent calendar arithmetic or the explicitly inspected time/conversion rule. Date serials use the tested default reference date; they do not show native GUI date formatting.

Put =DATE(2025;1;31) in A2 and =DATE(2025;2;28) in B2. =MONTHS(A2;B2;0) returns 1, because the ending date is the last day of its month. Moving B2 to February 27 returns 0. This month-end exception is useful to recognize when comparing periods anchored on the 31st.

For January 15 to April 15, mode 0 gives 3 and mode 1 gives 2. Choose the mode from the actual endpoint definition you need, rather than from the word Complete in a column heading.

If the desired quantity is the difference between year/month coordinates, a separate expression is clearer: with A2 containing January 1, 2025 and B2 containing February 1, 2025, use =(YEAR(B2)-YEAR(A2))*12+MONTH(B2)-MONTH(A2). The equivalent explicit-date formula was executed and returned 1. It counts month boundaries without making a complete-elapsed-month claim.

For contrast, the following native MONTHS mode-1 expression returned zero. Its result follows the unconditional advance of the starting month, even when that date is already the first.

=MONTHS(DATE(2025;1;1);DATE(2025;2;1);1)

The executed result was 0.

Reversed dates are not reordered before this calculation. Day-sensitive decrements can make reverse results asymmetric, so do not blindly negate a forward result. Invalid date text and a division-by-zero date both produced 1,503 in the shown boundary cases rather than errors. An erroneous type converted to zero. The two-argument call is invalid; omitting the mode does not select a default.

• Function-specific implementation
• Versioned help
• Date Conversion
• Integer Conversion
• Integer Floor
• Reference Date

The selected callbacks, date/time module and inspected conversion/time helpers are byte-identical between the retained 25.04.2 and 26.08.2 sources. This establishes source continuity for the described paths, not execution of the later release.

DATE, MONTH, EDATE.