>>>It's an interest rate on a boat - I don't have any more information here, so I wanted to see the most general term.
>>
>>Simple interest or compound interest? Fixed rate or variable?
>>
>>Start here:
>>http://www.discoverboating.com/buying/financing/loancalculator.aspx
>
>I like this reply by a customer of this application:
>
>I am fine with 360 or 365.
>
>At the end of the day it is still just a calculation so there is always the chance it can differ by a bit.
>
>:))

It'll be a very long day, then. Or a very short day... depending on which way the calculation builds more interest for the bank. I've seen many interesting approaches, and they can be quite creative.

As someone said, "when you read the small print, you gain wisdom; when you don't, experience".

The definition of month, year, day etc may vary from case to case. The "we calculate interest first" translates into "we charge interest upon interest". Administrative fees create windfall for the bank. YMMV. If in doubt, don't be in debt :).