Calcutta Is Located in Debian Tzdata-Legacy

7 Aug 2024
2-minute read

For those running Debian and derivatives: is Emacs' worldclock showing Bangalore ASIA instead of IST? One option: apt install tzdata-legacy.

In Emacs:

M-x world-clock

should show something like:

Seattle   Wednesday 07 August 11:54 PDT
New York  Wednesday 07 August 14:54 EDT
London    Wednesday 07 August 19:54 BST
Paris     Wednesday 07 August 20:54 CEST
Bangalore Thursday 08 August 00:24 IST
Tokyo     Thursday 08 August 03:54 JSTT

If any of the answers is off, like this:

Bangalore Wednesday 07 August 18:54 ASIA

then might you want to install tzdata-legacy. Maybe.

Context

At the beginning of 2024, Debian revised tzdata. From the /usr/share/doc/tzdata/NEWS.Debian.gz:

[…] the tzdata package ships only timezones that follow the current rules of geographical region (continent or ocean) and city name. All legacy timezone symlinks (old or merged timezones mentioned in the upstream backward file) were moved to tzdata-legacy. […]

In other words, in Debian Testing and Unstable, tzdata no longer lists:

  /usr/share/zoneinfo/Asia/Calcutta

It does list:

  /usr/share/zoneinfo/Asia/Kolkata

Calcutta and other legacy placenames are now in tzdata-legacy.

Choices!

The other option would be to modify the:

  world-clock-list

to use Kolkata, after all the city's name since 2001, Wikipedia shows.

  ("Asia/Kolkata" "Bangalore")

Like this:

  (setopt world-clock-list '(("America/Los_Angeles" "Seattle")
			     ("America/New_York" "New York")
			     ("Europe/London" "London")
			     ("Europe/Paris" "Paris")
			     ("Asia/Kolkata" "Bangalore")
			     ("Asia/Tokyo" "Tokyo")))

I asked about this on the emacs-devel mailing list. The maintainers have already made this change to Emacs master, writing:

It's safe to change time.el to use Asia/Kolkata now, as the standard name changed in 2008 and even ancient systems keep up with TZDB in order to function properly.

debian,emacs