Hi Chris,
Does the calendar system usually define whether leap-seconds are taken into account or not? In other words, given knowledge of which calendar system is in use, could a library make the correct calculation? Or is other information needed too?
Presumably this would only affect real-world calendars, and perhaps only UTC?
Cheers, Jon
-----Original Message-----
From: cf-metadata-bounces at cgd.ucar.edu [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf Of Lynnes, Christopher S. (GSFC-6102)
Sent: 19 August 2011 12:46
To: John Caron
Cc: cf-metadata at cgd.ucar.edu
Subject: Re: [CF-metadata] CDM calendar date handling
On Aug 18, 2011, at 6:23 PM, "John Caron" <caron at unidata.ucar.edu> wrote:
>> In order to do calculations
>> with times, which are often necessary, we need to be able to convert
>> them into a form which has a fixed-length unit since a reference time
>> (like udunits), even though that isn't the most convenient way to express them.
> I think that given two calendar dates in the same calendar, there will
> be a well-defined # seconds between them.
Yes...and no. There is the question of leap seconds. In the satellite data world, most people account for them, but not everyone. Some (most?) off the shelf packages do not.
--
Chris Lynnes
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Received on Fri Aug 19 2011 - 05:54:53 BST
