From: Jason Creighton <androflux@...>
Date: 2003-07-24T13:10:59+09:00
Subject: Re: SMTP Date format?

On Thu, 24 Jul 2003 00:32:33 +0900
Ben Giddings <ben@thingmagic.com> wrote:

> While we're on the subject though, what's the recommended method for 
> determining your timezone offset in Ruby?

~$ ri Time
This is a test 'ri'. Please report errors and omissions
on http://www.rubygarden.org/ruby?RIOnePointEight

------------------------------------------------------------------------
     class: Time
------------------------------------------------------------------------
     Time is an abstraction of dates and times. Time is stored
     internally as the number of seconds and microseconds since the
     epoch, January 1, 1970 00:00 UTC. On some operating systems, this
     offset is allowed to be negative. Also see the library modules Date
     and ParseDate, documented beginning on pages ?? and ??,
     respectively. The Time class treats GMT (Greenwich Mean Time) and
     UTC (Coordinated Universal Time)[Yes, UTC really does stand for
     Coordinated Universal Time. There was a committee involved.] as
     equivalent. GMT is the older way of referring to these baseline
     times but persists in the names of calls on Posix systems.
     All times are stored with some number of microseconds. Be aware of
     this fact when comparing times with each other---times that are
     apparently equal when displayed may be different when compared.

------------------------------------------------------------------------
     +, -, <=>, asctime, at, ctime, day, dst?, getgm, getlocal, getutc,
     gm, gmt?, gmt_offset, gmtime, gmtoff, hour, isdst, local,
     localtime, mday, min, mktime, mon, month, new, now, sec, strftime,
     times, to_a, to_f, to_i, to_s, tv_sec, tv_usec, usec, utc, utc,
     utc?, utc_offset, wday, yday, year, zone
------------------------------------------------------------------------
~$ ri Time.gmt_offset
This is a test 'ri'. Please report errors and omissions
on http://www.rubygarden.org/ruby?RIOnePointEight

-------------------------------------------------------- Time#gmt_offset
     time.gmt_offset -> aFixnum
------------------------------------------------------------------------
     Returns the offset in seconds between the timezone of time and UTC.
        t = Time.gm(2000,1,1,20,15,1)   #=> Sat Jan 01 20:15:01 UTC 2000
        t.gmt_offset                    #=> 0
        l = t.getlocal                  #=> Sat Jan 01 14:15:01 CST 2000
        l.gmt_offset                    #=> -21600

Jason Creighton