1Contributing to the tz code and data 2 3The time zone database is by no means authoritative: governments 4change timekeeping rules erratically and sometimes with little 5warning, the data entries do not cover all of civil time before 61970, and undoubtedly errors remain in the code and data. Feel 7free to fill gaps or fix mistakes, and please email improvements 8to tz@iana.org for use in the future. In your email, please give 9reliable sources that reviewers can check. 10 11----- 12 13Developers can contribute technical changes to the source code and 14data as follows. 15 16To email small changes, please run a POSIX shell command like 17'diff -u old/europe new/europe >myfix.patch', and attach 18myfix.patch to the email. 19 20For more-elaborate changes, please read the theory.html file and browse 21the mailing list archives <https://mm.icann.org/pipermail/tz/> for 22examples of patches that tend to work well. Additions to 23data should contain commentary citing reliable sources as 24justification. Citations should use https: URLs if available. 25 26Please submit changes against either the latest release in 27<https://www.iana.org/time-zones> or the master branch of the development 28repository. If you use Git the following workflow may be helpful: 29 30 * Copy the development repository. 31 32 git clone https://github.com/eggert/tz.git 33 cd tz 34 35 * Get current with the master branch. 36 37 git checkout master 38 git pull 39 40 * Switch to a new branch for the changes. Choose a different 41 branch name for each change set. 42 43 git checkout -b mybranch 44 45 * Edit source files. Include commentary that justifies the 46 changes by citing reliable sources. 47 48 * Debug the changes, e.g.: 49 50 make check 51 make install 52 ./zdump -v America/Los_Angeles 53 54 * For each separable change, commit it in the new branch, e.g.: 55 56 git add northamerica 57 git commit 58 59 See recent 'git log' output for the commit-message style. 60 61 * Create patch files 0001-*, 0002-*, ... 62 63 git format-patch master 64 65 * After reviewing the patch files, send the patches to tz@iana.org 66 for others to review. 67 68 git send-email master 69 70 * Start anew by getting current with the master branch again 71 (the second step above). 72 73Please do not create issues or pull requests on GitHub, as the 74proper procedure for proposing and distributing patches is via 75email as illustrated above. 76 77----- 78 79This file is in the public domain. 80