1 Contributing to the tz code and data
3 The time zone database is by no means authoritative: governments
4 change timekeeping rules erratically and sometimes with little
5 warning, the data entries do not cover all of civil time before
6 1970, and undoubtedly errors remain in the code and data. Feel
7 free to fill gaps or fix mistakes, and please email improvements
8 to tz@iana.org for use in the future.
10 To email small changes, please run a POSIX shell command like
11 'diff -u old/europe new/europe >myfix.patch', and attach
12 myfix.patch to the email.
14 For more-elaborate changes, please read the Theory file and browse
15 the mailing list archives <http://mm.icann.org/pipermail/tz/> for
16 examples of patches that tend to work well. Ideally, additions to
17 data should contain commentary citing reliable sources as
20 Please submit changes against either the latest release in
21 <ftp://ftp.iana.org/tz/> or the master branch of the experimental
22 Git repository. If you use Git the following workflow may be helpful:
24 * Copy the experimental repository.
26 git clone https://github.com/eggert/tz.git
29 * Get current with the master branch.
34 * Switch to a new branch for the changes. Choose a different
35 branch name for each change set.
37 git checkout -b mybranch
39 * Edit source files. Include commentary that justifies the
40 changes by citing reliable sources.
42 * Debug the changes, e.g.:
46 ./zdump -v America/Los_Angeles
48 * For each separable change, commit it in the new branch, e.g.:
53 See recent 'git log' output for the commit-message style.
55 * Create patch files 0001-*, 0002-*, ...
57 git format-patch master
59 * After reviewing the patch files, send the patches to tz@iana.org
64 * Start anew by getting current with the master branch again
65 (the second step above).
67 Please do not create issues or pull requests on GitHub, as the
68 proper procedure for proposing and distributing patches is via
69 email as illustrated above.