360/30 Accrual days

[IanWaterman]

This is not strictly a crystal problem, I just hope someone has had to create this formula before.

I am building a financial report which needs to calculate the accrual days of an investment. In some cases I must use what is known as the 360/30 method.

Eg 8/3/06 to 8/4/06 would normally be 32 days (system assumes investment from opening 8/3 to close 8/4), however, under 360/30 it would be 31 days. As it assumes all months are 30 days.

However, I am not totally clear on what happens happens when the start or end date is 31st.

Thanks in advance for any help.

Ian

 

[IanWaterman]

Found answer form another source, so here its is just incase someone else needs to do this.

//To find the size of an interest period, use this formula:
//
//360(Y2-Y1)+30(M2-M1)+(D2-D1)
//where Yn is the year, Mn is the month, and Dn is the number of days.
//However,if D1=31, set D1=30. If D2 is 31 and D1 is 30 or 31, change D2 to 30;
//otherwise,leave at 31.

local numbervar D1:= day({PeriodStart});
local numbervar D2:= day({PeriodEnd});
local numbervar M1:= month({PeriodStart});
local numbervar M2:= month({PeriodEnd});
local numbervar Y1:= year({PeriodStart});
local numbervar Y2:= year({PeriodEnd});

If D1 = 31 then D1:=30;
If D2 = 31 and D1 = 30 then D2:=30;

(360*(Y2-Y1))+(30*(M2-M1))+(D2-D1)+1;