tzdiff

Displays Timezone differences with localtime in CLI (shell script)

Tzdiff or Timediff ?

This command was originally "timediff". Now, it's "tzdiff" because of naming conflict.

Usage

tzdiff [-0] [-n count] [-f format] [-t time] timezone [timezone ...] [count] [0]

Tzdiff with no arguments will display list of timezones. Tzdiff with timezone will display the time differences of remote time with local time.

Options

• -h: show usage
• -0: round down to hour
• -n count: max hours (default: 10)
• -f format: output format (using '+output_fmt' of date(1))
• -t time: set the start time instead of current time. 'YYYY-mm-ddTHH:MM' or 'YYYYmmddTHHMM' is ok.
• -H: became the scripting mode. Fields are explicitly separated by single tab instead of an arbitrary space.
• -HH: became the scripting mode without timzone name.
• -N: display without local timezone.

Install

FreeBSD

If you are pkg user, you can easy to install tzdiff like this.

$ sudo pkg install tzdiff

Of course, it is already in ports. You can easy to play with ports.

macOS

If you are MacPorts user, you can easy to install tzdiff.

$ sudo port install tzdiff

If you are Homebrew user, you can install by personal tap.

$ brew tap belgianbeer/minmin
$ brew install tzdiff

Debian / Ubuntu

Currently, tzdiff become a debian pkg in progress. ( tzdiff in Debin pkg ) In near future, it can easy to install by apt command.

$ sudo apt update
$ sudo apt install tzdiff

Examples

In these examples, author's timezone is JST.

$ tzdiff
Africa/         Australia/      Etc/            MST             WET
America/        CET             Europe/         MST7MDT         posixrules
Antarctica/     CST6CDT         Factory         PST8PDT         zone.tab
Arctic/         EET             HST             Pacific/
Asia/           EST             Indian/         SystemV/
Atlantic/       EST5EDT         MET             UTC

$ tzdiff America/Los_Angeles
America/Los_Angeles
2017-05-12 05:55 PDT    2017-05-12 21:55 JST
2017-05-12 06:55 PDT    2017-05-12 22:55 JST
2017-05-12 07:55 PDT    2017-05-12 23:55 JST
2017-05-12 08:55 PDT    2017-05-13 00:55 JST
2017-05-12 09:55 PDT    2017-05-13 01:55 JST
2017-05-12 10:55 PDT    2017-05-13 02:55 JST
2017-05-12 11:55 PDT    2017-05-13 03:55 JST
2017-05-12 12:55 PDT    2017-05-13 04:55 JST
2017-05-12 13:55 PDT    2017-05-13 05:55 JST
2017-05-12 14:55 PDT    2017-05-13 06:55 JST

Tzdiff supports TIMEZONE's completion. For example,

$ tzdiff Lon             # enter RETURN instead of TAB
Arctic/Longyearbyen     Europe/London

$ tzdiff Lond
Europe/London
2017-05-31 07:10 BST    2017-05-31 15:10 JST
2017-05-31 08:10 BST    2017-05-31 16:10 JST
2017-05-31 09:10 BST    2017-05-31 17:10 JST
2017-05-31 10:10 BST    2017-05-31 18:10 JST
2017-05-31 11:10 BST    2017-05-31 19:10 JST
2017-05-31 12:10 BST    2017-05-31 20:10 JST
2017-05-31 13:10 BST    2017-05-31 21:10 JST
2017-05-31 14:10 BST    2017-05-31 22:10 JST
2017-05-31 15:10 BST    2017-05-31 23:10 JST
2017-05-31 16:10 BST    2017-06-01 00:10 JST

$ tzdiff New_ 0 5
America/New_York
2017-05-12 08:00 EDT    2017-05-12 21:00 JST
2017-05-12 09:00 EDT    2017-05-12 22:00 JST
2017-05-12 10:00 EDT    2017-05-12 23:00 JST
2017-05-12 11:00 EDT    2017-05-13 00:00 JST
2017-05-12 12:00 EDT    2017-05-13 01:00 JST

It is easy to check changes from daylight saving time to standard time

$ tzdiff -t 2017-11-05T11:00 Los New_ Brus
America/Los_Angeles     America/New_York        Europe/Brussels
2017-11-04 19:00 PDT    2017-11-04 22:00 EDT    2017-11-05 03:00 CET    2017-11-05 11:00 JST
2017-11-04 20:00 PDT    2017-11-04 23:00 EDT    2017-11-05 04:00 CET    2017-11-05 12:00 JST
2017-11-04 21:00 PDT    2017-11-05 00:00 EDT    2017-11-05 05:00 CET    2017-11-05 13:00 JST
2017-11-04 22:00 PDT    2017-11-05 01:00 EDT    2017-11-05 06:00 CET    2017-11-05 14:00 JST
2017-11-04 23:00 PDT    2017-11-05 01:00 EST    2017-11-05 07:00 CET    2017-11-05 15:00 JST
2017-11-05 00:00 PDT    2017-11-05 02:00 EST    2017-11-05 08:00 CET    2017-11-05 16:00 JST
2017-11-05 01:00 PDT    2017-11-05 03:00 EST    2017-11-05 09:00 CET    2017-11-05 17:00 JST
2017-11-05 01:00 PST    2017-11-05 04:00 EST    2017-11-05 10:00 CET    2017-11-05 18:00 JST
2017-11-05 02:00 PST    2017-11-05 05:00 EST    2017-11-05 11:00 CET    2017-11-05 19:00 JST
2017-11-05 03:00 PST    2017-11-05 06:00 EST    2017-11-05 12:00 CET    2017-11-05 20:00 JST

Tzdiff works with the following operating systems.

• macOS / FreeBSD / NetBSD / OpenBSD (It may work on DragonFly BSD.)
• Debian / Ubuntu / CentOS and many Linux distros
• Windows subsystem for Linux