On 3/31/07, rhubarb <rover.rhubarb / gmail.com> wrote:
> Is this a bug?
> I'm trying to get ruby to format a date, time or datetime to the proper
> format for xmltv.
> they key is in the timezone - I want it in +0100 format.
>
> So look at this irb session.
>
> First create some summer and winter dates in the form of Date, Time and
> DateTime - they all have a time component but this always comes out
> zeroed in Date.strftime as expected.
>
> Im concentrating on the %z here because that's what's supposed to give
> me the +0100 that I want.
>
>
> Okay now lets create some summer and winter times:
>
> irb(main):001:0> require 'date'
> => true
>
> ### Summer
>
> irb(main):005:0> d_summer = Date.parse("1 August 2006 15:25")
> => #<Date: 4907897/2,0,2299161>
>
> irb(main):006:0> t_summer = Time.parse("1 August 2006 15:25")
> => Tue Aug 01 15:25:00 GMT Daylight Time 2006
>
> irb(main):007:0> dt_summer = DateTime.parse("1 August 2006 15:25")
> => #<DateTime: 706737353/288,0,2299161>
>
> ### Winter
>
> irb(main):008:0> d_winter = Date.parse("1 November 2006 15:25")
> => #<Date: 4908081/2,0,2299161>
>
> irb(main):009:0> t_winter = Time.parse("1 November 2006 15:25")
> => Wed Nov 01 15:25:00 GMT Standard Time 2006
>
> irb(main):010:0> dt_winter = DateTime.parse("1 November 2006 15:25")
> => #<DateTime: 706763849/288,0,2299161>
>
> ### Now format the times
>
> irb(main):011:0> d_winter.strftime('%z')
> => "+0000"
> irb(main):012:0> d_summer.strftime('%z')
> => "+0000"
> irb(main):013:0> t_winter.strftime('%z')
> => "GMT Standard Time"
> irb(main):014:0> t_summer.strftime('%z')
> => "GMT Daylight Time"
> irb(main):015:0> dt_winter.strftime('%z')
> => "+0000"
> irb(main):016:0> dt_summer.strftime('%z')
> => "+0000"
>
>
> See what's happening: Time always gives the full string for the
> timezone, and it correctly varies it for summer versus winter: "GMT
> Standard Time" vs "GMT Daylight Time"
>
> Now Date, and DateTime give me the numeric format I wanted. The winter
> format is correct for me - I'm on GMT in winter, but look at the Summer
> format: _it's the same as for Winter_
>
> It seems to me that if Time.strftime makes the difference, then Date and
> DateTime should too.
> I expected to see +0100 for the summer times. And so does my Media
> Center for that matter, so this will cause my EPG to be off by an hour
> unless I correct it myself.
>
> Anyone else noticed this?
>
> I understand the system strftime is used by ruby, so I guess it might be
> in Windows (I'm using XP). I haven't programmed in C on this windows
> box, but I have in C#, and there I get the correct result from
> dateTime.ToString("yyyyMMddHHmmss zzzz"), which no-doubt is using some
> .Net framework version of the time routine, not the same one as ruby.
>
> Anyway, this is a bug right?
> Is it specific to windows (XP, SP2 is what I'm using)
>
> If it is a bug is it fixed or fixable?
> Is there an easy way to correct - it?  A different Time support class?
> (I was thinking of just parsing the output from Time.strftime for the
> "Daylight" and creating my own string.
>
> (I'm in Portugal by the way, and writing this during daylight savings at
> the end of March, so my current tz is GMT Daylight Time - same as the
> UK)

I get the same results in my Fedora Core 6 system (ruby-1.8.5.35),
except that I don't seem to have Time.parse.

-- 
Felipe Contreras