WEEKDAY

Quirk found

Category: Date and time · Last tested 2026-08-06

Real, executed compatibility results for the WEEKDAY function across Microsoft Excel, Google Sheets, and LibreOffice Calc — verified by actually running it. Syntax and links to each vendor’s official documentation are below.

Support matrix

Engine	Documented	Live-tested	Verdict
Excel	Yes	Not yet	n/a
Google Sheets	Yes	Not yet	n/a
LibreOffice Calc	Yes	Yes (25.8.7.3, 2026-08-06)	Quirk found

LibreOffice version history

We executed the same test cases under each LibreOffice release to show exactly when WEEKDAY’s support changed — not documentation claims, real results.

LibreOffice version	Verdict	Tested
24.2.0.3	Quirk found	2026-07-19
24.8.7.2	Quirk found	2026-07-19
25.2.0.3	Quirk found	2026-07-24
25.8.7.3	Quirk found	2026-08-06

Why isn't WEEKDAY working in LibreOffice?

WEEKDAY exists in LibreOffice 25.8.7.3, but it is not a drop-in match for Excel — our executed tests found real behavioral differences (detailed in the test results on this page). If a formula that works in Excel or Google Sheets misbehaves in LibreOffice, compare your usage against the failing cases above before assuming your data is wrong.

Discovered quirks

=WEEKDAY(DATE(2008,2,14),99) on LibreOffice Calc returned #VALUE!, but the documented/expected result is #NUM!. Microsoft docs: an invalid return_type raises #NUM!.; MISMATCH vs expected: expected '#NUM!', got '#VALUE!'

Executed test cases

LibreOffice Calc 25.8.7.3 (tested 2026-08-06)

Formula	Description	Result	Expected	Verdict
=WEEKDAY(DATE(2008,2,14))	Default return_type 1: Sunday=1..Saturday=7. Feb 14, 2008 is a Thursday. Source: https://support.microsoft.com/en-us/office/weekday-function-60e44483-2ed1-439f-8bd0-e404c190949a (worked example, WEEKDAY(A2)=5)	5	5	Matched
=WEEKDAY(DATE(2008,2,14),2)	return_type 2: Monday=1..Sunday=7. Source: Microsoft WEEKDAY docs worked example, WEEKDAY(A2,2)=4.	4	4	Matched
=WEEKDAY(DATE(2008,2,14),3)	return_type 3: Monday=0..Sunday=6 (zero-based). Thursday is 3 in this scheme.	3	3 Per Microsoft's return_type table, mode 3 maps Monday..Sunday to 0..6; Thursday (the 4th weekday counting Monday=0) = 3.	Matched
=WEEKDAY(DATE(2008,2,14),12)	return_type 12: Tuesday=1..Monday=7 (ISO-style variant start day). Thursday is the 3rd day in this scheme.	3	3 Per Microsoft's return_type table, mode 12 maps Tuesday=1,Wed=2,Thu=3,...,Monday=7.	Matched
=WEEKDAY(DATE(2008,2,14),16)	return_type 16: Saturday=1..Friday=7. Thursday is the 6th day in this scheme.	6	6 Per Microsoft's return_type table, mode 16 maps Saturday=1,Sun=2,Mon=3,Tue=4,Wed=5,Thu=6,Fri=7.	Matched
=WEEKDAY(DATE(2008,2,14),99)	An out-of-range return_type (not one of the documented 1,2,3,11-17 values) is a documented error condition.	#VALUE!	#NUM! Microsoft docs: an invalid return_type raises #NUM!.	Mismatch

Docs & syntax

Excel: official documentation
Google Sheets: official documentation
LibreOffice Calc: official documentation