Timezone and NTP
================

The instructions here are a summary of the information in the Ubuntu
documentation [1]_.

Timezone
--------

All nodes operating in DataONE must report times in UTC_. 

Coordinating nodes MUST have their system timezones set to UTC. This can be
set during the OS installation, in Ubuntu the UTC selection is at the bottom of
the menu choices.

Alternatively, the system timezone can be set to UTC after installation by the
following steps from the command line::

  echo "Etc/UTC" | sudo tee "/etc/timezone"
  sudo dpkg-reconfigure --frontend noninteractive tzdata


For OS X users, UTC display in the world clock desktop widget can be enabled
[2]_ by editing */Library/Widgets/World Clock.wdgt/WorldClock.js* and adding
an entry::

  {city:'GMT/UTC', offset:0, timezone:'UTC', id:"2647937"},

to the Europe group. 


Network Time Protocol
---------------------

All nodes (and ideally clients as well) participating in DataONE should use a
mechanism to ensure the system clocks are kept up-to-date. The NTP daemon [3]_
monitors the system clock and adjusts as necessary. To install *ntpd* on
ubuntu::

  sudo apt-get install ntp

Also verify the contents of */etc/ntp.conf* to check the specified time servers
includes::

  server ntp.ubuntu.com
  server pool.ntp.org

*pool.ntp.org* utilizes round robin DNS to randomly select a timeserver.


----

.. [1] https://help.ubuntu.com/community/UbuntuTime
.. [2] http://lategahn.2log.de/index.php?utc-gmt-zulu-for-the-mac-world-clock
.. [3] http://www.ntp.org/

.. _UTC: http://en.wikipedia.org/wiki/Coordinated_Universal_Time