COUPDAYBS

COUPDAYBS(settlement, maturity, frequency [,basis])

Returns the number of days between the previous coupon date and the settlement date.

settlement	The settlement date of the security.
maturity	The maturity date of the security.
frequency	The number of coupon payments in a year: 1 = annual 2 = semi annual 4 = quarterly
basis	(Optional) The type of day counting to use: 0 = 30/360 (default) 1 = Actual/Actual 2 = Actual/360 3 = Actual/365 4 = 30E/360

REMARKS

* "BS" is an abbreviation for before settlement.
* The "settlement" is the date a buyer purchases a coupon, such as a bond.
* The "maturity" is the date when the security expires.
* Dates must be entered as text strings within quotation marks or as serial numbers.
* If "settlement" >= "maturity", then #NUM! is returned.
* If "settlement" is not an integer, it is truncated.
* If "settlement" is not a valid date, then #NUM! is returned.
* If "maturity" is not an integer, it is truncated.
* If "maturity" is not a valid date, then #NUM! is returned.
* If "maturity" has passed, then #VALUE! is returned.
* If "frequency" is not an integer, it is truncated.
* If "frequency" is any number other than 1, 2 or 4, then #NUM! is returned.
* If "basis" is left blank then 0 is used.
* If "basis" is not an integer, it is truncated.
* If "basis" < 0, then #NUM! is returned.
* If "basis" > 4, then #NUM! is returned.
* You can use the COUPDAYS function to return the number of days between the coupon dates on either side of the settlement date.
* You can use the COUPDAYSNC function to return the number of days between the settlement date and the next coupon date.
* You can use the COUPNCD function to return the next coupon date after the settlement date.
* You can use the COUPNUM function to return the number of coupons between the settlement date and the maturity date.
* You can use the COUPPCD function to return the previous coupon date before the settlement date.
* For the Microsoft documentation refer to support.microsoft.com
* For the Google documentation refer to support.google.com

	A
1	=COUPDAYBS("6 Jan 2011", "31 Dec 2012", 2, 0) = 6.0
2	=COUPDAYBS("6 Jan 2011", "31 Dec 2012", 2, 1) = 6.0
3	=COUPDAYBS("25/1/2007", "15/11/2008", 2, 1) = 71.0
4	=COUPDAYBS("1/25/2003", "11/15/2004", 2, 1) = #VALUE!
5	=COUPDAYBS("1/25/1998", "11/15/1999", 2, 1) = #VALUE!

1 - How many days are there between the previous coupon date and the settlement date if you purchase a bond on 6 Jan 2011 that matures on 31 Dec 2012 when coupons are paid semi-annually and day count is 30/360.
2 - How many days are there between the previous coupon date and the settlement date if you purchase a bond on 6 Jan 2011 that matures on 31 Dec 2012 when coupons are paid semi-annually and day count is Actual/Actual.