# Documentation/Calc Functions/COUPDAYBS

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COUPDAYBS

## Category:

Financial Analysis

## Summary:

Uses a bond’s maturity date, the frequency of the bond’s coupon payments, and the applicable day count convention to determine the latest coupon date that falls on or before the specified settlement date. The function then calculates and returns the number of days between that coupon date and the settlement date.

## Syntax:

COUPDAYBS(Settlement; Maturity; Frequency[; Basis])

## Returns:

Returns an integer value in the range 0 to 365 (inclusive), which is the number of days between the latest coupon date that falls on or before the settlement date, and the settlement date.

## Arguments:

Settlement is a date (in quotation marks) or a date-time serial number, or a reference to a cell containing one of those types, which specifies when a trade is "settled". On this date the seller completes the transfer of the bond to the buyer, and the buyer makes the appropriate payment to the seller.

Maturity is a date (in quotation marks) or a date-time serial number, or a reference to a cell containing one of those types, which specifies when the bond matures. On maturity, the bond issuer must repay the bond holder the full amount of the bond.

Frequency is a positive integer, or a reference to a cell containing that integer, that is the number of coupons paid per year. Valid values are 1 (annual), 2 (semiannual), or 4 (quarterly).

Basis is an integer in the range 0 to 4, or a reference to a cell containing that integer, which indicates how the year is to be calculated. For more background information, visit Wikipedia's Day count convention page.

Basis Calculation
0 or missing US method (NASD), 12 months of 30 days each
1 Exact number of days in months, exact number of days in year.
2 Exact number of days in month, year has 360 days.
3 Exact number of days in month, year has 365 days.
4 European method, 12 months of 30 days each.
• If either Settlement or Maturity is not a valid date expression, then COUPDAYBS reports a #VALUE! error.
• If the Settlement date is on or after the Maturity date then COUPDAYBS reports an invalid argument error (Err:502).
• If Frequency is non-numeric, then COUPDAYBS reports a #VALUE! error.
• If Basis is non-numeric, then COUPDAYBS reports an invalid argument error (Err:502).
• If either Basis or Frequency is a non-integer value, then COUPDAYBS truncates it to an integer value.
• If, after any truncation, Frequency is not equal to 1, 2, or 4, then COUPDAYBS reports an invalid argument error (Err:502).
• If, after any truncation, Basis is not equal to 0, 1, 2, 3, or 4, then COUPDAYBS reports an invalid argument error (Err:502).

• The examples on this page use the standard ISO 8601 format for dates because this should be independent of your selected locale settings. The default date format on your computer may be different. Avoid using locale dependent date formats which may produce errors if the document is loaded under different locale settings. It is often good practice to utilize the DATE function instead of typing formatted date values.
• If either Settlement or Maturity includes time components, they are ignored by COUPDAYBS.
• For more background information about coupons, visit Wikipedia’s Coupon (finance) page.

## Examples:

Formula Description Returns
=COUPDAYBS(A1; A2; A3; A4) where cell A1 contains the date 2022-09-01, cell A2 contains the date 2025-11-15, cell A3 contains the number 2, and cell A4 contains the number 3. An investor purchases a bond with a maturity date of 2025-11-15, with the trade settled on 2022-09-01. The bond pays interest every six months and the applicable day count convention is basis 3 (exact number of days in month, 365 days in year). Here the function calculates back from the maturity date to determine the latest coupon date that falls on or before 2022-09-01 and returns the number of days between that coupon date and the settlement date. 109
=COUPDAYBS("2022-09-01"; "2022-11-15"; 2) An investor purchases a bond with a maturity date of 2025-11-15, with the trade settled on 2022-09-01. The bond pays interest every six months. Since the fourth argument is omitted, COUPDAYBS defaults to a day count convention of basis 0 (12 months of 30 days each). Here the function calculates back from the maturity date to determine the latest coupon date that falls on or before 2022-09-01 and returns the number of days between that coupon date and the settlement date. 106
=COUPDAYBS(DATE(2022; 9; 1); DATE(2025; 11; 15); 2) Here the formula performs the same function as in the previous example but utilizes the DATE function instead of typing formatted date values. 106
=COUPDAYBS(44805; 45976; 2) Calc treats dates as numbers, where each date corresponds to a date-time serial number. Assuming that the Date option at Tools ▸ Options ▸ LibreOffice Calc ▸ Calculate (LibreOffice ▸ Preferences ▸ LibreOffice Calc ▸ Calculate on macOS) is set to its default value, 44805 is the date-time serial number for 2022-09-01 and 45976 is the date-time serial number for 2025-11-15. Here the formula performs the same function as in the previous example. 106

COUPDAYBS