Hi all,
I'm trying to understand how to handle some climate data with a 360-day
calendar. As I understand it
(
http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.ht
ml#calendar), this calendar uses 12-month years with exactly 30 days
each. I have a few questions:
1) In this system, how long is a day in milliseconds? Is it the normal
24*60*60*1000? Or is it somehow scaled so that a year of 360 days has
the same number of milliseconds as an "average" Gregorian year?
2) Is there any way of translating (even roughly) between 360-day and
Gregorian calendars? E.g. perhaps one could, for a given date-time,
calculate the fraction of a year that has elapsed and apply this in the
conversion? Or is the comparison only meaningful in a statistical sense
(e.g. annual/seasonal averages)?
3) Would the most usual way to encode a CF time axis in a 360-day
calendar be to use "days since..."? I guess if a day has a standard
length in (milli)seconds then one could also safely use "seconds
since..."?
4) Finally on practical note: I seem to remember that someone has
implemented the 360-day calendar using the Java library joda-time? Is
this code available for re-use?
Thanks in advance,
Jon
--
Dr Jon Blower
Technical Director, Reading e-Science Centre
Environmental Systems Science Centre
University of Reading
Harry Pitt Building, 3 Earley Gate
Reading RG6 6AL. UK
Tel: +44 (0)118 378 5213
Fax: +44 (0)118 378 6413
j.d.blower at reading.ac.uk
http://www.nerc-essc.ac.uk/People/Staff/Blower_J.htm
Received on Thu Feb 04 2010 - 04:14:25 GMT
