What is a year dependent fiscal year variant ?

In a year dependent fiscal year variant the number of days in a month are not as per the calendar month. Let us take an example:- For the year 2005 the period January ends on 29th, Feb ends on 27th, March ends on
29. For the year 2006 January ends on 30th, Feb ends on 26th, March ends on 30th. This is applicable to many countries especially USA. Ever year this fiscal year variant needs to be configured in such a case