Date bench

datebench.rb

#!/usr/bin/env ruby
require 'benchmark'
require 'date'

Benchmark.bm do|b|
  ITERATE = 100000
  
  b.report("strptime") do
    time = "2011-05-25 00:00:03 -0400"
    fmt  = "%Y-%m-%d %H:%M:%S %z"
    ITERATE.times { DateTime.strptime(time, fmt) }
  end

  b.report("parse") do
    time = "2011-05-25 00:00:03 -0400"
    ITERATE.times { DateTime.parse(time) }
  end
end

Aaaand one with JRuby:

jruby 1.6.6 (ruby-1.8.7-p357) (2012-01-30 5673572) (Java HotSpot(TM) 64-Bit Server VM 1.6.0_29) [darwin-x86_64-java]
              user     system      total        real
strptime 22.628000   0.000000  22.628000 ( 22.589000)
parse    15.086000   0.000000  15.086000 ( 15.086000)