[tz] Preparing to fork tzdb

[Paul Eggert]

On 9/26/21 6:03 PM, Guy Harris wrote:
> (Paul, I think, constructed the tz Git repository, in part, from the original SCCS history from when SCCS was being used by Arthur).

Yes, about a decade ago I wrote some one-off software to convert 
Arthur's entire SCCS repository into a Git repository before tzcode2012c 
and tzdata2012d were released. Although we never had competing 
repositories or a fork or anything like that, a handful of changes were 
"in the air" during the conversion from SCCS to Git.

In the Git log, all commits that were converted from SCCS contain 
something like "SCCS-file: northamerica" and "SCCS-SID: 8.53" in their 
commit messages; each of these commits affects just one file because 
that was the SCCS way, and the SCCS SIDs are file-specific.

The last SCCS version corresponds to Git commit 
07dbc825cb32f2ae9b7f5d980ba31680a8e92b53, authored 2012-03-03 13:26:39 
-0500, and the first Git-only commit is the next one (its parent, in 
Gitese), commit c0f1e5d9d6c7959f73506e992a0e3ba2b0c5c5e8, authored 
2012-03-02 05:21:33 UTC (although this timestamp precedes that of the 
other commit, that's allowed in Git). Some cleanup commits appear soon 
after the conversion, interspersed with non-cleanup commits.