This directory contains tools for time zone updates.

Data update tools
=================

download-iana-data.py
  - A helper script run before update-tzdata.py.
    It downloads the latest tzdata update from IANA and puts it in
    the system/timezone/input_data/iana directory for use by the
    update-tzdata.py script.

    There are sometimes code and metadata changes associated
    with tzdata updates that should be applied to ICU at the same time.
    e.g. see http://bugs.icu-project.org/trac/search?q=2015d

update-tzdata.py
  - Regenerates the external/icu and system/timezone/output_data timezone
    data files.

    CTS tests for ICU, bionic and libcore should be run before and after.