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. 9 10To email small changes, please run a POSIX shell command like 11'diff -u old/europe new/europe >myfix.patch', and attach 12myfix.patch to the email. 13 14For more-elaborate changes, please read the Theory file and browse 15the mailing list archives <http://mm.icann.org/pipermail/tz/> for 16examples of patches that tend to work well. Ideally, additions to 17data should contain commentary citing reliable sources as 18justification. 19 20Please submit changes against either the latest release in 21<ftp://ftp.iana.org/tz/> or the master branch of the development 22repository. If you use Git the following workflow may be helpful: 23 24 * Copy the development repository. 25 26 git clone https://github.com/eggert/tz.git 27 cd tz 28 29 * Get current with the master branch. 30 31 git checkout master 32 git pull 33 34 * Switch to a new branch for the changes. Choose a different 35 branch name for each change set. 36 37 git checkout -b mybranch 38 39 * Edit source files. Include commentary that justifies the 40 changes by citing reliable sources. 41 42 * Debug the changes, e.g.: 43 44 make check 45 make install 46 ./zdump -v America/Los_Angeles 47 48 * For each separable change, commit it in the new branch, e.g.: 49 50 git add northamerica 51 git commit 52 53 See recent 'git log' output for the commit-message style. 54 55 * Create patch files 0001-*, 0002-*, ... 56 57 git format-patch master 58 59 * After reviewing the patch files, send the patches to tz@iana.org 60 for others to review. 61 62 git send-email master 63 64 * Start anew by getting current with the master branch again 65 (the second step above). 66 67Please do not create issues or pull requests on GitHub, as the 68proper procedure for proposing and distributing patches is via 69email as illustrated above. 70 71----- 72 73This file is in the public domain. 74