On Thu, 18 Aug 2011 16:15:27 +0200, [UTF-8?]SaaÅ¡ha Metsärantala wrote
> Hello!
> > The date 2012-02-30 using the (very short lived) Swedish calendar is 
still a valid date
> Well, 1712-02-30 is "valid" in this calendar, but not in the (gregorian) 
> astronomical one and thus nothing for today's EDTF without conversion. 

There are a very large number of calendars. Some like the Swedish are no 
longer in use but others like the Hebrew/Jewish are still actively being 
used and developed. Dates from one to the other must be converted. Sometimes 
its easy.. and sometimes its quite difficult or possible only with lower 

> AFAIK, no plans were ever made at all to consider 2012-02-30 as a valid 
> date within the Swedish calendar. Have you some references about the 
> "2012-02-30" issue?

Do not confuse a calendar with its common use. The Swedish calendar 
became "obsolete" in 1711 when Sweden decided to return to a Julian based 
calendar starting in 1712. A day was added to the leap year allowing for a 
30 Feb 1712. While the calendar used was more or less Julian based it did 
have a number of "Swedish tweeks". After 40 years of evolutionary tweeking 
(a tradition of self-declared "Revolutions in little steps")of the Julan 
calendar Sweden adopted yet another calendar: the Gregorian (well not 
really.. more a Swedish variant but..).
[as a side note on use: its quite common for computer programs to internally 
use a Julian calendar to store dates given the simplicity of arithmetic over 
the International (Gregorian).]

The whole point is.. These are all unique calendars and not the same as the 
International calendar currently in use.. 

> Anyway, maybe we could just keep a record of this issue and move this 
> discussion to the next phase.
> Regards!
> [UTF-8?]Saašha,


Edward C. Zimmermann, NONMONOTONIC LAB
Umsatz-St-ID: DE130492967