ws-calendar — archive

FW: [tc-xml-l] Durations and DST

From: Toby Considine
To: [email protected]
Date: Mon, 24 Jan 2011 03:24:00 -0000

A clarification from Mike on Durations… The key statement to my mind is P2D is not equal to PT48H right through the year In a similar way, if I am specifying a Month, then I had better count the days myself… We may wish to conform some types of down-stream uses of WS-Calendar to use Hours only, if it comes to that. tc "If something is not worth doing, it`s not worth doing well" - Peter Drucker Toby Considine TC9, Inc TC Chair: oBIX & WS-Calendar TC Editor: EMIX, EnergyInterop U.S. National Inst. of Standards and Tech. Smart Grid Architecture Committee Email: [email protected] Phone: (919)619-2104 http://www.tcnine.com/ blog: www.NewDaedalus.com From: Mike Douglass [mailto:[email protected]] Sent: Sunday, January 23, 2011 10:20 PM To: [email protected] Cc: 'tc-xml-l tc-xml-l Reflector'; [email protected] Subject: Re: [tc-xml-l] Durations and DST From RFC5545 The duration of a week or a day depends on its position in the calendar. In the case of discontinuities in the time scale, such as the change from standard time to daylight time and back, the computation of the exact duration requires the subtraction or addition of the change of duration of the discontinuity. Leap seconds MUST NOT be considered when computing an exact duration. When computing an exact duration, the greatest order time components MUST be added first, that is, the number of days MUST be added first, followed by the number of hours, number of minutes, and number of seconds. In Java(tm) implementation terms you cold use the Calendar class and work through the fields adding the appropriate values and the class takes account of DST transitions. So a day could be 23/24/25 hours. If it's important to have an exact number of hours then you specify as hours, that is P2D is not equal to PT48H right through the year On 01/23/2011 09:43 PM, Toby Considine wrote: A duration of 15 days, 5 hours, and 20 seconds would be: P15DT5H0M20S How many hours is that? If one of those days is the 23 hour day (or 25 hour day) to begin oe ened Daylight Savings Time, what is the understanding? If the Duration starts at 3:00 PM, would it end at 8:00 PM, 7:00 PM, or 9:00 PM tc “It is difficult to get a man to understand something, when his salary depends upon his not understanding it” -- Upton Sinclair. Toby Considine TC9, Inc OASIS Technical Advisory Board TC Chair: oBIX & WS-Calendar TC Editor: EMIX, EnergyInterop U.S. National Inst. of Standards and Tech. Smart Grid Architecture Committee Email: [email protected] Phone: (919)619-2104 http://www.tcnine.com/ blog: www.NewDaedalus.com _______________________________________________ tc-xml-l mailing list [email protected] http://lists.calconnect.org/mailman/listinfo/tc-xml-l -- Mike Douglass [email protected] Senior Systems Programmer Communication & Collaboration Technologies 518 276 6780(voice) 2809 (fax) Rensselaer Polytechnic Institute 110 8th Street, Troy, NY 12180