the same formula, replacing Date2 by Date3. In general, coupon payments will vary from period to period, due to the differing number of days in the periods. The formula applies to both regular and irregular coupon periods. Other names: Act/360 A/360 French Sources: ICMA Rule 251.1(i) (not sterling). ISDA 2006 Section 4.16(e). Actual/364 Formulas: Each month is treated normally and the year is assumed to be 364 days. For example, in a period from February 1, 2005 to April 1, 2005, the Factor is considered to be 59 days divided by 364. The CouponFactor uses the same formula, replacing Date2 by Date3. In general, coupon payments will vary from period to period, due to the differing number of days in the periods. The formula applies to both regular and irregular coupon periods. Actual/365L Here L stands for Leap year. Formulas: This convention requires a set of rules in order to determine the days in the year (DiY). If Freq = 1 (annual coupons): If February 29 is in the range from Date1 (exclusive) to Date2 (inclusive), then DiY = 366, else DiY = 365. If Freq <> 1: If Date2 is in a leap year, then DiY = 366, else DiY = 365. The CouponFactor uses the same formula, replacing Date2 by Date3. In general, coupon payments will vary from period to period, due to the differing number of days in the periods. The formula applies to both regular and irregular coupon periods. Other names: ISMA-Year Sources: ICMA Rule 251.1(i) (Euro-sterling floating-rate notes). Actual/Actual AFB Formulas: This convention requires a set of rules in order to determine the days in the year (DiY). The basic rule is that if February 29 is in the range from Date1 (inclusive) to Date2 (exclusive), then DiY = 366, else DiY = 365. If the period from Date1 to Date2 is more than one year, the calculation is split into two parts: the number of complete years, counted back from the last day of the period the remaining initial stub, calculated using the basic rule. As an example, a period from 1994-02-10 to 1997-06-30 is split as follows: 1994-06-30 to 1997-06-30 = 3 (whole years calculated backwards from the end) 1994-02-10 to 1994-06-30 = 140/365 Resulting in a total value of 3 + 140/365. This convention was originally written in French and during translation the term "Période d'Application" was converted to "Calculation Period". As