NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
Hi- Just to follow up on the issue that arose regarding dates. Last week I said:
I will look into the unit parsing for this case though. I'm pretty sure that the underlying VisAD unit parsing only handles UTC, GMT and Z as valid timezones. I'll see if we can ammend that.
The background is that the unit specification: hours since 2003-12-01 00:00:00MDT was not taken as a valid unit. In looking at the description of the ISO spec for time (ISO 8601) found at: http://www.cl.cam.ac.uk/%7Emgk25/iso-time.html parsing of a time zone like "MDT" can be problematic. To quote from that reference:"There exists no international standard that specifies abbreviations for civil time zones like CET, EST, etc. and sometimes the same abbreviation is even used for two very different time zones. In addition, politicians enjoy modifying the rules for civil time zones, especially for daylight saving times, every few years, so the only really reliable way of describing a local time zone is to specify numerically the difference of local time to UTC".
Given that information, I am not going to make any changes to the unit parsing to handle time zone specifications other than Z, UTC or GMT (which the underlying VisAD unit parsing already supports). As a side note, CF specifies that unit specifications should be udunitscompatible and at first glance udunits gives no error for the unit specification "hours since 2003-12-01 00:00:00MDT". In this case,
the MDT is ignored, so it takes it as GMT anyway. udunits does support the +/-hh:mm format and that is what should be used. Don ************************************************************* Don Murray UCAR Unidata Program dmurray@xxxxxxxxxxxxxxxx P.O. Box 3000 (303) 497-8628 Boulder, CO 80307 http://www.unidata.ucar.edu/staff/donm "Time makes everyone interesting, even YOU!" *************************************************************
idvdevelopers archives: