Fixed Asset Days Calculation

Hi, I am running v4 and trying to calculate depreciation for the period 28/02/05 - 28/03/05 (the last depreciation was posted on 27/02/2005). By my reckoning this should be 29 days, but the system is suggesting that this is 31 days??? I am not and nor do I wish to use force no. of days. There is a strange calculation in the Depreciation Calculation codeunit (5616) which seems to be causing the problem. Has anyone else experienced this problem??? Why is it not a simple case of applying the date filters to the system Date table and simply counting the records?

Navision bases it months on being 30 days and the year being 360 days. Therefore from the 27 Feb to 28 March there are 3 Feb days and 28 march days giving 31. If you run the next one to 10 April there will be 12 days 29 & 30 of March and 10 April days. All comes right in the wash.