Hi Russell, I developed an open source .NET API which you might find helpful with your C# application which is available at: http://www.codeplex.com/zoneinfo I have a codeproject article about it as well at: http://www.codeproject.com/KB/locale/zoneinfo_dotnet_api.aspx You can read through the code if you are interested in seeing how I interpreted this information. Kind regards Mark Rodrigues Subject: RE: tz file format Date: Sun, 7 Jun 2009 01:55:29 -0400 From: Billy.Bennett@netapp.com To: tz@lecserver.nci.nih.gov Russ, I think you'd be better off parsing the compiled data, it's a lot more consistent. Thanks, =Billy Bennett From: russ [mailto:russell.sayers@gmail.com] Sent: Saturday, June 06, 2009 11:53 PM To: tz@lecserver.nci.nih.gov Subject: tz file format Hi, I hope i'm not wasting your time. I'm attempting to read the tz database into a c# application, and I'm not sure how to interpret this entry: Zone Australia/Hobart 9:49:16 - LMT 1895 Sep 10:00 - EST 1916 Oct 1 2:00 10:00 1:00 EST 1917 Feb 10:00 Aus EST 1967 10:00 AT EST What is the significance of the "1:00" on the row ending in "1917 Feb". Do I just add this to the 10:00 offset? Thanks, Russell