the last day of February), then change D2 to 30. If the investment is EOM and (Date1 is the last day of February), then change D1 to 30. If D2 is 31 and D1 is 30 or 31, then change D2 to 30. If D1 is 31, then change D1 to 30. This convention is used for US corporate bonds and many US agency issues. It is most commonly referred to as "30/360", but the term "30/360" may also refer to any of the other conventions of this class, depending on the context. Other names: 30U/360 - 30U/360 is not strictly the same as 30/360, it is used for the Euribor (Euro denominated Libor) curve and Euro denominated swaps, with the distinction that under 30/360, each day in a 31-day month accrues 30/31 of interest, whereas in 30U/360 payment occurs on the 30th and the 31st is considered to be part of the next month. - Bloomberg 30/360 Sources: ISDA 2006 Section 4.16(f), though the first two rules are not included. 30E/360 Date adjustment rules: If D1 is 31, then change D1 to 30. If D2 is 31, then change D2 to 30. Other names: 30/360 ICMA 30/360 ISMA 30S/360 Eurobond basis (ISDA 2006) Special German Sources: ICMA Rule 251.1(ii), 251.2. ISDA 2006 Section 4.16(g). 30E/360 ISDA Date adjustment rules: If D1 is the last day of the month, then change D1 to 30. If D2 is the last day of the month (unless Date2 is the maturity date and M2 is February), then change D2 to 30. Other names: 30E/360 ISDA Eurobond basis (ISDA 2000) German Sources: ISDA 2006 Section 4.16(h). Actual methods The conventions of this class calculate the number of days between two dates (e.g., between Date1 and Date2) as the Julian day difference. This is the function Days(StartDate, EndDate). The conventions are distinguished primarily by the amount of the CouponRate they assign to each day of the accrual period. Actual/Actual ICMA Formulas: For regular coupon periods where Date2 and Date3 are equal: For irregular coupon periods, the period has to be divided into one or more quasi-coupon periods (also called notional periods) that match the normal frequency of payment dates. The interest in each such period (or partial period) is then computed, and then the amounts are summed over the number of quasi-coupon periods. For details, see or the ISDA paper. This method ensures that all