Hi Paul, thanks for your help, the new tracing seems to reveal a diff in the abbreviations. Regards Manu -----Original Message----- From: Paul Eggert <eggert@cs.ucla.edu> Sent: Montag, 3. Mai 2021 20:17 To: Manuela Friedrich <Manuela.Friedrich@actian.com> Cc: Steven Shuriff <Steven.Shuriff@actian.com>; Time zone mailing list <tz@iana.org> Subject: Re: iana build failures on Windows Hmm, it looks like my previous diagnosis was incorrect. Perhaps the problem is with the abbreviations, not the offsets. Please try the attached zdump-test.diff patch instead (this is against the current development commit a16541786b0d8c9746de8ed558c861550fdc3bc3 dated Apr 26 09:49:29 2021 -0700). What is your output of 'zdump -v Africa/Abidjan' with this patch? My output zdump-Abidjan.txt is attached for comparison.