ACT ACT

Subtype of Name

The ISDA convention, also known as Actual/Actual (Historical), Actual/Actual, Actual/Actual ISDA, and according to ISDA also Actual/365, Act/365, and A/365
Let [T₁,T₂) be the period between two dates T₁ and T₂, of which the length L in annual units must be calculated
Calculation rule:
Let N₁ be the actual number of days of the period [T₁,T₂) that happen to fall in a leap year
Let N₂ be the actual number of days of the period [T₁,T₂) that happen to fall in a normal year
Then
L = N1/366 + N2/365