Financial

COUPDAYBS Function in Excel

Returns the number of days from the beginning of the coupon period to the settlement date.

Syntax

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

Arguments

  • settlement (required): Settlement date
  • maturity (required): Maturity date
  • frequency (required): Payments per year (1, 2, or 4)
  • basis (optional): Day count basis

Examples

  • =COUPDAYBS("1/25/2024", "11/15/2027", 2) - Days from coupon start - Result: 71

COUPDAYBS modeling tips

  • Align rate and period units (annual rate ÷ 12 for monthly models).
  • Use consistent cash-flow signs (outflows negative, inflows positive).
  • Hub: [Financial functions guide](/guides/excel-financial-functions-guide/).

Common errors

  • #NUM! if dates invalid

Use cases

  • Bond pricing
  • Accrued interest
  • Fixed income

Frequently asked questions

  • What is the COUPDAYBS function in Excel? COUPDAYBS returns the number of days from the beginning of the coupon period to the settlement date. The syntax is =COUPDAYBS(settlement, maturity, frequency, [basis]). Typical use cases include bond pricing, accrued interest, fixed income.
  • How do I use the COUPDAYBS function? To use COUPDAYBS, type =COUPDAYBS( in a cell and provide the required arguments. Excel will show you the syntax and parameter hints as you type. Make sure to close the parentheses and press Enter to execute the function.
  • Why is COUPDAYBS not working in my Excel? Common issues with COUPDAYBS include #NUM! if dates invalid. Start by checking the syntax =COUPDAYBS(settlement, maturity, frequency, [basis]), then verify each referenced cell or range.

Editorial review

  • Reviewed by Excel.Directory Editorial Team. Updated May 2026.