DateTime.parse handles them correctly, and DateTime.parse.to_time
results in the correct time.  Time.parse doesn't handle them
correctly because Time.zone_offset uses a different regexp that
only considers hours and minutes, not seconds.
[ruby-core:83400] [Bug #14034]

From: Jeremy Evans <code@jeremyevans.net>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60216 b2dd03c8-39d4-4d8f-98ff-823fe69b080e