$ jirb
;irb(main):001:0> require 'parsedate'
=> true
irb(main):002:0> res = ParseDate.parsedate('Wed, 10 Oct 2007 11:55:23 -0700')
=> [2007, 10, 10, 11, 55, 23, "-0700", 3]
irb(main):003:0> date = Time.gm(*res)
ArgumentError: Argument out of range.
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb/workspace.rb:52:in `eval'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb/workspace.rb:81:in `evaluate'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb/context.rb:219:in `evaluate'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb.rb:150:in `eval_input'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb.rb:70:in `signal_status'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb.rb:147:in `eval_input'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb.rb:70:in `each_top_level_statement'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb.rb:146:in `loop'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb/ruby-lex.rb:230:in `each_top_level_statement'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb.rb:146:in `catch'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb/ruby-lex.rb:229:in `each_top_level_statement'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb.rb:146:in `eval_input'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb.rb:70:in `start'
from :1:in `catch'
from /usr/local/jruby-1.0.1/lib/ruby/1.8/irb.rb:69:in `start'
from :1
Maybe IRB bug!!

It seems that the date parser does not like this particular format. Note that "Tue Aug 28 00:37:29 2007 -0700" (JRUBY-1298) works just fine.

~/NetBeansProjects/jruby $ cat test.rb
require 'parsedate'
res = ParseDate.parsedate('Wed, 10 Oct 2007 11:55:23 -0700')
p Time.gm(*res)
~/NetBeansProjects/jruby $ ruby test.rb
Wed Oct 10 11:55:23 UTC 2007

Note that the output timezone is still UTC, rather than -0700 or CST or whatever. According to the JRuby implementation of Time.gm, it's expecting to get a microsecond value where the "-0700" appears in the parsed array.

Here's the rdoc for Time.gm. Note that there's no form that takes the sequence of values parsedate seems to produce, and that the only ones that accept timezone also take weekday, year day, and a DST flag:

--------------------------------------------------------------- Time::gm
     Time.utc( year [, month, day, hour, min, sec, usec] ) => time
     Time.utc( sec, min, hour, day, month, year, wday, yday, isdst, tz
     ) => time
     Time.gm( year [, month, day, hour, min, sec, usec] ) => time
     Time.gm( sec, min, hour, day, month, year, wday, yday, isdst, tz
     ) => time
------------------------------------------------------------------------
     Creates a time based on given values, interpreted as UTC (GMT). The
     year must be specified. Other values default to the minimum value
     for that field (and may be +nil+ or omitted). Months may be
     specified by numbers from 1 to 12, or by the three-letter English
     month names. Hours are specified on a 24-hour clock (0..23). Raises
     an +ArgumentError+ if any values are out of range. Will also accept
     ten arguments in the order output by +Time#to_a+.

        Time.utc(2000,"jan",1,20,15,1)  #=> Sat Jan 01 20:15:01 UTC 2000
        Time.gm(2000,"jan",1,20,15,1)   #=> Sat Jan 01 20:15:01 UTC 2000

So perhaps Ruby is just ignoring bogus input for some parameters?

MRI also allows negative usec values by overflowing.

MRI doesn't allow usec values that don't fit in a signed int. Should we follow MRI here? I used the long min value since we already use the long max value.