COUPDAYBS
Quirk foundCategory: Financial · Last tested 2026-09-01
Real compatibility results for the COUPDAYBS function: executed in Excel for the web, Google Sheets and LibreOffice Calc, with desktop Excel behavior from Microsoft’s official documentation (we do not run desktop Excel — Excel for the web is a different application and is executed separately). Syntax and links to that documentation are below.
Support matrix
| Engine | Documented | Live-tested | Verdict |
|---|---|---|---|
| Excel (desktop) | Yes | No — documented only | n/a |
| Excel for the web | — | Yes (recalc, 2026-09-01) | Supported, behaves as documented |
| Google Sheets | Yes | Yes (Drive import, 2026-08-31) | Supported, behaves as documented |
| LibreOffice Calc | Yes | Yes (25.8.7.3, 2026-08-31) | Quirk found |
LibreOffice version history
We executed the same test cases under each LibreOffice release to show exactly when COUPDAYBS’s support changed — not documentation claims, real results.
| LibreOffice version | Verdict | Tested |
|---|---|---|
| 24.2.0.3 | Quirk found | 2026-08-31 |
| 24.8.7.2 | Quirk found | 2026-08-31 |
| 25.2.0.3 | Quirk found | 2026-08-31 |
| 25.8.7.3 | Quirk found | 2026-08-31 |
Why isn't COUPDAYBS working in LibreOffice?
COUPDAYBS 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
-
=COUPDAYBS(A2,A3,3,A5) on
LibreOffice Calc returned
#VALUE!, but the documented/expected
result is #NUM!.
Provenance
Excel documents: "If frequency is any number other than 1, 2, or 4, COUPDAYBS returns the #NUM! error value."; MISMATCH vs expected: expected '#NUM!', got '#VALUE!'
-
=COUPDAYBS(A2,A3,A4,5) on
LibreOffice Calc returned
#VALUE!, but the documented/expected
result is #NUM!.
Provenance
Excel documents: "If basis < 0 or if basis > 4, COUPDAYBS returns the #NUM! error value."; MISMATCH vs expected: expected '#NUM!', got '#VALUE!'
-
=COUPDAYBS(A3,A2,A4,A5) on
LibreOffice Calc returned
#VALUE!, but the documented/expected
result is #NUM!.
Provenance
Excel documents: "If settlement >= maturity, COUPDAYBS returns the #NUM! error value."; MISMATCH vs expected: expected '#NUM!', got '#VALUE!'
Executed test cases
Excel for the web (executed 2026-09-01 via OneDrive recalculation)
These values come from Excel for the web, not from desktop Excel. They are two different implementations of the calculation engine, and this run measured only the web one: the corpus was uploaded to OneDrive as .xlsx, recalculated by Excel for the web on open, and downloaded again for readback. Excel for the web is a rolling service with no pinnable version, so the run is identified by its date. Where a value here disagrees with the Expected column — which is Microsoft’s documentation of the desktop product — we cannot tell you whether the web engine diverges from the desktop one or the documentation is wrong about both, because we do not run desktop Excel.
| Formula | Description | Result | Expected | Verdict |
|---|---|---|---|---|
| =COUPDAYBS(A2,A3,A4,A5) | Microsoft's documented worked example: days from the start of the coupon period to settlement, semiannual, actual/actual | 71 | 71ProvenanceMicrosoft's page publishes this example's result as 71. Setup serials are the dates Microsoft's page prints: 40568 = 2011-01-25 (settlement), 40862 = 2011-11-15 (maturity), frequency 2 (semiannual), basis 1 (actual/actual). Counting coupon dates back from maturity in six-month steps gives 2011-11-15, 2011-05-15, 2010-11-15, so the settlement date falls in the coupon period 2010-11-15 to 2011-05-15. On basis 1 the count is the actual number of days from 2010-11-15 to 2011-01-25: 15 remaining days in November + 31 in December + 25 in January = 71, confirmed by Python date subtraction |
Matched |
| =COUPDAYBS(A2,A3,A4,0) | The same bond on the US (NASD) 30/360 basis instead of actual/actual | 70 | 70ProvenanceBasis 0 is documented as US (NASD) 30/360, which counts every month as 30 days: from 2010-11-15 to 2011-01-25 that is (2011-2010)*360 + (1-11)*30 + (25-15) = 360 - 300 + 10 = 70, one day fewer than the actual/actual 71. This case discriminates the basis argument, which the documented example alone does not |
Matched |
| =COUPDAYBS(A2,A3,3,A5) | A frequency of 3, which is not one of the permitted values | #NUM! | #NUM!ProvenanceExcel documents: "If frequency is any number other than 1, 2, or 4, COUPDAYBS returns the #NUM! error value." |
Matched |
| =COUPDAYBS(A2,A3,A4,5) | A day-count basis of 5, above the documented maximum of 4 | #NUM! | #NUM!ProvenanceExcel documents: "If basis < 0 or if basis > 4, COUPDAYBS returns the #NUM! error value." |
Matched |
| =COUPDAYBS(A3,A2,A4,A5) | Settlement and maturity swapped, so settlement is after maturity | #NUM! | #NUM!ProvenanceExcel documents: "If settlement >= maturity, COUPDAYBS returns the #NUM! error value." |
Matched |
Google Sheets (executed 2026-08-31 via Drive import)
Google Sheets is a rolling service with no pinnable version, so this run is identified by its date. The corpus was imported to Drive as .xlsx, recalculated by Sheets, and exported back for readback.
| Formula | Description | Result | Expected | Verdict |
|---|---|---|---|---|
| =COUPDAYBS(A2,A3,A4,A5) | Microsoft's documented worked example: days from the start of the coupon period to settlement, semiannual, actual/actual | 71 | 71ProvenanceMicrosoft's page publishes this example's result as 71. Setup serials are the dates Microsoft's page prints: 40568 = 2011-01-25 (settlement), 40862 = 2011-11-15 (maturity), frequency 2 (semiannual), basis 1 (actual/actual). Counting coupon dates back from maturity in six-month steps gives 2011-11-15, 2011-05-15, 2010-11-15, so the settlement date falls in the coupon period 2010-11-15 to 2011-05-15. On basis 1 the count is the actual number of days from 2010-11-15 to 2011-01-25: 15 remaining days in November + 31 in December + 25 in January = 71, confirmed by Python date subtraction |
Matched |
| =COUPDAYBS(A2,A3,A4,0) | The same bond on the US (NASD) 30/360 basis instead of actual/actual | 70 | 70ProvenanceBasis 0 is documented as US (NASD) 30/360, which counts every month as 30 days: from 2010-11-15 to 2011-01-25 that is (2011-2010)*360 + (1-11)*30 + (25-15) = 360 - 300 + 10 = 70, one day fewer than the actual/actual 71. This case discriminates the basis argument, which the documented example alone does not |
Matched |
| =COUPDAYBS(A2,A3,3,A5) | A frequency of 3, which is not one of the permitted values | #NUM! | #NUM!ProvenanceExcel documents: "If frequency is any number other than 1, 2, or 4, COUPDAYBS returns the #NUM! error value." |
Matched |
| =COUPDAYBS(A2,A3,A4,5) | A day-count basis of 5, above the documented maximum of 4 | #NUM! | #NUM!ProvenanceExcel documents: "If basis < 0 or if basis > 4, COUPDAYBS returns the #NUM! error value." |
Matched |
| =COUPDAYBS(A3,A2,A4,A5) | Settlement and maturity swapped, so settlement is after maturity | #NUM! | #NUM!ProvenanceExcel documents: "If settlement >= maturity, COUPDAYBS returns the #NUM! error value." |
Matched |
LibreOffice Calc 25.8.7.3 (tested 2026-08-31)
| Formula | Description | Result | Expected | Verdict |
|---|---|---|---|---|
| =COUPDAYBS(A2,A3,A4,A5) | Microsoft's documented worked example: days from the start of the coupon period to settlement, semiannual, actual/actual | 71 | 71ProvenanceMicrosoft's page publishes this example's result as 71. Setup serials are the dates Microsoft's page prints: 40568 = 2011-01-25 (settlement), 40862 = 2011-11-15 (maturity), frequency 2 (semiannual), basis 1 (actual/actual). Counting coupon dates back from maturity in six-month steps gives 2011-11-15, 2011-05-15, 2010-11-15, so the settlement date falls in the coupon period 2010-11-15 to 2011-05-15. On basis 1 the count is the actual number of days from 2010-11-15 to 2011-01-25: 15 remaining days in November + 31 in December + 25 in January = 71, confirmed by Python date subtraction |
Matched |
| =COUPDAYBS(A2,A3,A4,0) | The same bond on the US (NASD) 30/360 basis instead of actual/actual | 70 | 70ProvenanceBasis 0 is documented as US (NASD) 30/360, which counts every month as 30 days: from 2010-11-15 to 2011-01-25 that is (2011-2010)*360 + (1-11)*30 + (25-15) = 360 - 300 + 10 = 70, one day fewer than the actual/actual 71. This case discriminates the basis argument, which the documented example alone does not |
Matched |
| =COUPDAYBS(A2,A3,3,A5) | A frequency of 3, which is not one of the permitted values | #VALUE! | #NUM!ProvenanceExcel documents: "If frequency is any number other than 1, 2, or 4, COUPDAYBS returns the #NUM! error value." |
Mismatch |
| =COUPDAYBS(A2,A3,A4,5) | A day-count basis of 5, above the documented maximum of 4 | #VALUE! | #NUM!ProvenanceExcel documents: "If basis < 0 or if basis > 4, COUPDAYBS returns the #NUM! error value." |
Mismatch |
| =COUPDAYBS(A3,A2,A4,A5) | Settlement and maturity swapped, so settlement is after maturity | #VALUE! | #NUM!ProvenanceExcel documents: "If settlement >= maturity, COUPDAYBS returns the #NUM! error value." |
Mismatch |
Docs & syntax
- Excel (desktop): official documentation
- Google Sheets: official documentation
- LibreOffice Calc: official documentation