ACT 365F

Subtype of Name

Actual/365 convention, also known as Act/365 (Fixed), A/365 (Fixed), or A/365F
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 N be the actual number of days of the period [T₁,T₂), formally defined as the difference: T₂ - T₁
Then
L = N/365
Warning: According to ISDA, "Actual/365" (without "Fixed") is an alias for "Actual/Actual (ISDA)" (see ActualActual.)
If Actual/365 is not explicitly specified as fixed in an instrument specification, you might want to double-check its meaning.