Setting a Custom Time Zone

You can update the time zone database information on JUNOS routers independently of the JUNOS operating system. This feature simplifies time zone management in JUNOS systems by allowing for future unforeseen time zone database adjustments. You can configure your router to use a custom time zone database file that you create to meet your requirements by editing an existing time zone database file.

Usage Guidelines for Setting a Custom Time Zone

To use a custom time zone, follow these steps:

1. Download a time zones archive (from a known or designated source) to the router. Compile the time zone archive using the zic time zone compiler, which generates tz files.
2. Using the CLI, configure the router to enable the use of the generated tz files as follows:
   [edit]
   # set system use-imported-timezones
3. If the above setting is made, the following command will show the imported time zones (saved in the directory /var/db/zoneinfo/):
   # set system time-zone ?

   Otherwise, the JUNOS default time zones are shown (saved in the directory /usr/share/zoneinfo/).

How to Import and Install Time Zone Files

To import and install time zone files, follow these steps:

1. Download the time zone files archive and untar them to a tmp directory:
   # mkdir -p /var/tmp/tz && cd /var/tmp/tz && rm *
   # wget 'ftp://elsie.nci.nih.gov/pub/tzdata*.tar.gz'
   # tar xvzf tzdata*.gz
   
   africa
   antarctica
   asia
   australasia
   europe
   northamerica
   southamerica
   pacificnew
   etcetera
   factory
   backward
   systemv
   solar87
   solar88
   solar89
   iso3166.tab
   zone.tab
   leapseconds
   yearistype.sh

   Note: If needed, you can edit the above untarred files to create or modify time zones.

2. Select the names of time zone files to compile and feed them to the following script.
   For example, to generate northamerica and asia tz files:
   # /usr/libexec/ui/compile-tz northamerica asia
3. Enable the use of the generated tz files using the CLI:
   [edit]
   # set system use-imported-time-zones
   
   [edit]
   # set system time-zone ?
   

   This should show the newly generated tz files in /var/db/zoneinfo/.

4. Set the time zone and commit:
   [edit]
   # set system time-zone <your-time-zone>
   # commit
5. Verify that the time zone change has taken effect:
   [edit]
   # run show system uptime