The day-count convention for CDS spreads is actual/ 360 (similar to floating legs of interest-rate swap). The actual/ 360 Is used to determine the actual number of days that have gone by since the beginning of an interest accrual interval. Actual/ 360 is calculated by dividing the actual number of days by 360. The resulting figure is, then, used in finding out the amount of interest that has accrued on a fixed income instrument. The actual/ 360 is the basis for calculating the interest due on money market instruments.

Since the day-count conventions for bond credit spreads (such as a bond’s asset swap spread or z-spread) is typically also actual/ 360, which makes such credit spreads directly comparable to the CDS spread.