A couple of doubts

[Mike Leone]

Conscious User had this to say:
> Hi Mike, thanks for the reply.
> 
>> 1) There is no way for GnuCash (or any other accounting package) to know 
>> in advance how much you actually pay on any bill. That's why you have to 
>> enter the amount that you DO pay. Not "intentions" but actuality.
> 
> That's too bad. But is "paying the entire bill" that rare of a use case?

Certainly not rare. But last statistic I heard in the US was that 30%+ 
of people carried a balance on their credit cards ...

> 
> I'm surprised that no accounting package does this...

The fact that no package does should indicate that it is not as easy a 
thing to do as it may seem.

> 
>> 2) There are a zillion (OK, just dozens) of different ways that interest 
>> might be figured. In theory would be possible to code for a number of 
>> these different ways and provide a menu for users to select the 
>> particular method to apply to this account. In practice that wouldn't be 
>> very useful, prone to user error (wrong selection) and your records 
>> (when you made deposits or withdrawals) and the banks are unlikely to 
>> always agree precisely. More normal you wait till you have a statement 
>> form the bank and enter that month's interest.
>>
>>    If you don't understand what I meant by "different ways", could you 
>> be a bit more precise what you meant by that 0.5% interest? Was that 
>> 6%/365 times the average daily balance? Or was that 0.5%/30 times the 
>> average daily balance? Or does it matter how many actual days there were 
>> in the month? (with the first example it did).
> 
> I think I used the wrong words. What I what is very simple: my savings
> account to increase by 0.5% each month.

The same question applies. Do we add 0.5% of the ending balance? Do we 
accrue (0.5%/# of days in the period) on the average daily balance? Do 
you know the actual starting and ending dates of the monthly period, and 
have inputted them, so we know the proper number of days in this period? 
  etc

You see, it is not "very simple". Most banks accrue interest on the 
average daily balance. And if your "average daily balance" is different 
from their "average daily balance" (quite easy, if some transactions 
have not cleared in the period), then the calculation will be off.

Unless you've got dozens of accounts to enter interest income amounts 
for, it's much easier to just enter the information by hand, rather than 
compute it (and probably get it wrong).