Hello, If you add the start date you still don't know how long it is. 2005-08-09T18:31:42P6M4DT12H30M17S How many seconds is that? In this case we could agree that 5 months after 2005-08-09 is 2006-01-09 but I have to guess that more or less. It is not specified. And which date is 1 month after 2006-01-31 or 5 months after 2005-02-28 or even worse, 12 months after 2008-2-29. Perhaps the individual records will not be that long in general, but if the processing time for a huge number of processors is taken together, then you easily add up to a number of years. Perhaps, if you want to avoid big using numbers it is also an idea to specify that in durations a month is always 30 days, a year 365 days and a day is always 24 hours. Then the ISO8601 specification is not ambiguous. But I would prefer to use seconds. Best regards, Bart Heupers, HPC Advisor 31 (0) 20 592 8071 SARA, Kruislaan 415, 1098 SJ Amsterdam -----Original Message----- From: ur-wg-bounces@ogf.org [mailto:ur-wg-bounces@ogf.org] On Behalf Of Thomas Soddemann Sent: donderdag 21 september 2006 4:14 To: Mailing List for UR-WG Subject: Re: [UR-WG] Comment on duration format for WallDuration andCpuDuration Hi folks, ISO8601 allows to set the start date for a given period like in 2005-08-09T18:31:42P6M4DT12H30M17S which are 5 months, 4 days, 12hours 30 minutes and 17 seconds after 2005-08-09 18:31:42. So in principle there is no problem with using the ISO format. Personally, I prefer not to put any restriction on the ISO format. Only the timezone and hence the possible existence of daylight saving periods have to be known. E.g., in DEISA we are using UTC. Besides, ISO8601 is an official way to express date/time and time periods in the European Union (EN 28601) and Switzerland. Cheers, Thomas -- -------------------------------------------------- Dr. Thomas Soddemann | Boltzmannstrasse 2 Grid Architect | 85748 Garching Rechenzentrum der MPG | Germany am MPI fuer Plasmaphysik | --------------------------------------------------- phone: +49 89 3299 2694 | fax: +49 89 3299 1301 --------------------------------------------------- -- ur-wg mailing list ur-wg@ogf.org http://www.ogf.org/mailman/listinfo/ur-wg