Hello, I''ve filed a new bug: http://ironruby.codeplex.com/WorkItem/View.aspx?WorkItemId=2217 I think that times are off by an hour when converting to/from ints: If I type this into IronRuby:>>> Time.at(1252006743)=> Thu Sep 03 11:39:03 -07:00 2009 and into irb:>> Time.at(1252006743)=> Thu Sep 03 12:39:03 -0700 2009 Thanks, Martin