Jose,
In my idea does this never work as measuring system. Somehow I thought it is
not possible with the Gregorian Calender, every month can have a different
length you know, not to talk about leap years. Therefore it is not such a
good measuring system.
Therefore
Date - Date represented as year, months, will will give a total other
result in by instance days as you use another startdate and add your
measured result.
(Years, weeks, days) or (years, days) will do a better job.
Although the leap year problem sustains..
That is the reason that some people want to use this kind of calendars.
http://en.wikipedia.org/wiki/Positivist_Calendar
But just my thought.
Cor