view release on metacpan or  search on metacpan

lib/DMA/ISODate.pm  view on Meta::CPAN

If this all seems very ad hoc -- it is. Date formats are very ad hoc with 
ambiguities which can only be decided with contextual information. That's a 
job for people, not a poor wee ISODate Class.

Four digit year formats are not limited to 4 digits. We can express dates far
into the future. In any place hereafter where we use "YYYY", any number of 
extra digits are possible. 

[We aren't affected by the size of Unix timval (ie the 2038 max year) except 
it is not convenient right now to do a perpetual calendar of my own to check 
the validity of a date.]

We do not, however, have any means of representing dates BC. For this we might
consider using the Peter Kokh dating system which adds 10000 to the AD date to
represent all of human history after the end of the most recent Ice Age. This
allows much easier translation between all modern and ancient dating systems
if you remember there was no year zero as they had not gotten around to 
inventing nothing back then. (Given some recent discoveries offshore in India,
I might prefer adding 20000 years!)