This is fascinating and complicated stuff. I've just checked with my
Windows95 calendar and it reports that February in the year 2000 has 29
days, so it's final. Year 2000 is a leap year ;))))
           Now I'm no mathematician but I can't think of a year (at least
in the future) that's divisible by 400 and not divisible by 4, so can we do
away with the first rule ("divisible by 400")? That would leave "evenly
divisible by 4 AND not evenly divisible by 100". The next such year is 2100
(according to my truly poor math skills), that's 104 years from now. So
won't "divisible by four" do for now or is an exact calculation of leap
years necessary as we are actually producing systems that have an expected
life span of more than 100 years ? or perhaps our software calculations
take into account the next two centuries ? or perhaps this list only needs
a spark.....:)

Costas