[CF-metadata] udunits time units question

From: Schultz, Martin <m.schultz>
Date: Fri, 1 Apr 2011 08:55:45 +0200

Hi Chris et al.,

     indeed it seems like some clarification is necessary about the use of different calendars in modelling. Your suggestion to "map" the 360 day calendar onto the Gregorian calendar in output files won't work: there would be no need for a 360 day calendar if it would. The idea behind fixed-length-year calendars is precisely the opposite: preserve seasonality without having to deal with leap years etc. Of course you need to adjust the solar cycle accordingly, that means your model will have a solar year that is precisely 360 days long (and not 365.25 as in reality). If you were to map these dates onto the gregorian calendar, you would have to interpolate the time axis so that days 1 to 360 fit into the range 1 to 365 or 366, respectively. Yes - a converter 360-days (or 365-days) to gregorian (and reverse) could be written, but you would redce the number of your friends if you insist that this is the only valid way to represent time of the model output ;-)

    You are right that a date such as 1960-01-31 is invalid in a 360-day calendar, and indeed a smart tool should flag this as an error.

Hope this helps,

Martin



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Received on Fri Apr 01 2011 - 00:55:45 BST