Hi everyone,

I'd like to propose a trac ticket or two to clarify the meaning when using 
alternative calendars. But before I do that I'd like to check for community 
opinion (or even consensus!?) ...

1. Time zones should be excluded/banned when using non-real-world calendars. 
For example, the statement in section 4.4 of "if the time zone is omitted the 
default is UTC" should not apply.

2. The "months since" and "years since" semantics for non-real-world calendars 
need defining/outlawing. e.g. The UDUNITS definition of a year as 365.242198781 
days makes no sense at all for a 360-day calendar, but in this particular case 
a year could be unambiguously defined as 360 days.

3. The year-zero semantics for non-real-world calendars need defining. From 
section 7.4, "Year 0 may be a valid year in non-real-world calendars".

I have some further questions concerning real-world calendars, but as with all 
things dealing with the real world they are a little more messy so I'll save 
them for another post.

Richard Hattersley
Benevolent Dictator of Iris - a CF library for Python: 
www.scitools.org.uk/iris<http://www.scitools.org.uk/iris>
Met Office  FitzRoy Road  Exeter  Devon  EX1 3PB  United Kingdom
Tel: +44 (0)1392 885702
Email: 
[email protected]<mailto:[email protected]> 
 Web: www.metoffice.gov.uk<http://www.metoffice.gov.uk/>

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