(Posted to both The Unix Heritage Society and the TZ mailing list)

I've been off-and-on reading the "live minus thirty years" old usenet
feed at olduse.net, and noticed something that may be of interest to
both of these groups: The original mod.sources posting of the (as far as
I can tell) earliest available version of Arthur David Olson's timezone
handling code, in 1986.

https://groups.google.com/d/msg/mod.sources/gcolqTxTt9w/04ZtaYCxLvcJ

For the files present in both, it matches revision 7441f6b6 from the git
repository, except for SCCS IDs vs %W%.
https://github.com/eggert/tz/tree/7441f6b6705782743f40b9fc40cdcc80a498fda5

The git repository contains a file ialloc.c that is not present in the
release.

Probable renamed files - These appear in the git repository under their
new
names, but had the older names in the release.
New: localtime.c newctime.3 zdump.c zic.8 zic.c
Old: tzcomp.8 tzcomp.c tzdump.c settz.c settz.3

Files in the release but not this version of the git repository:

mkdir.c strchr.c: These never appear, though they're referenced in
Makefile edits.
pacificnew: doesn't appear until SCCS version 8.1 in revision aaf2a927
dated July 2006.
years.sh: Appears as SCCS 7.1 yearistype.sh, dated March 1992.