Re: syntax to specify time scales

2007-01-22 Thread Rick Measham
Zefram wrote: Rick Measham wrote: my $riyadh_lmt = DateTime::TimeZone::LMT->new( longitude => 46 + (43 / 60) + (27 / 3600) ); How much error in time conversions is introduced by the floating point rounding? DateTime allows for a one-second precision in the offset, so while LMT passes a f

Re: syntax to specify time scales

2007-01-22 Thread Eugene van der Pijll
Zefram schreef: > So *legally speaking* the standard time in the UK is based on what we > now call UT1. It is an astronomical timescale. I've read some of the relevant parliamentary debates now, and you're right. That still doesn't mean that our TZ Europe/London should be based on UT1: the time t

Re: syntax to specify time scales

2007-01-22 Thread Zefram
Eugene van der Pijll wrote: > it's the difference >between GPS and TAI(GPS) that is fixed, right? Forgot to reply to this earlier. Yes, strictly speaking the equation is TAI(GPS) = GPST + 19 s I've been using the term "GPS time" slight

Re: syntax to specify time scales

2007-01-22 Thread Zefram
Rick Measham wrote: >my $riyadh_lmt = DateTime::TimeZone::LMT->new( >longitude => 46 + (43 / 60) + (27 / 3600) >); How much error in time conversions is introduced by the floating point rounding? >A thought: it might be good to somehow include the ability to load other >TZ modules from a str

Re: syntax to specify time scales

2007-01-22 Thread Zefram
Eugene van der Pijll wrote: >> Civil time in the UK is not legally based on UTC; > >I believe this to be incorrect. British Standard Time, aka >"Europe/London", certainly observes leap seeconds, and is therefore >based on UTC. Maybe the legal definition is still in terms of GMT, (The name "British

Re: syntax to specify time scales

2007-01-22 Thread Rick Measham
Eugene van der Pijll wrote: If I were to implement these time scales for DateTime, I would probably implement them as subclasses of UT1 (or "LMT") and LAT, with the geographical longitude as parameter; "LMT+46d43m27s" for Riyadh legal time, for example. But your notation is reasonable as well.

Re: syntax to specify time scales

2007-01-22 Thread Eugene van der Pijll
Zefram schreef: > I note that DT::TZ::TAI > attempts to treat TAI as a timezone, which doesn't work 100% but does > put TAI in roughly the right relationship to the other DT objects. As you say, TZ::TAI does not work 100% prefectly. It has turned out to be impossible to implement it correctly, bec

Re: ANNOUNCE: Time::Local 1.14

2007-01-22 Thread kenichi ishigaki
Hi, Time::Local 1.14 is broken on Win32. You removed a test but forgot to decrease a skip count. Kenichi --- Local.t 2007-01-22 22:06:35.359375000 +0900 +++ Local.t.patched 2007-01-22 22:16:27.18750 +0900 @@ -168,7 +168,7 @@ SKIP: { -skip 'this platform does not support negative