How to use display-time-world to show time in specific time zones?

How to use display-time-world to show time in specific time zones?

[N. Jackson]

I'm wondering how to use display-time-world to display the time in
specific time zones.

The doc string for zoneinfo-style-world-list, which IIUC is the list of
time zones used by display-time-world says:

    zoneinfo-style-world-list is a variable defined in ‘time.el’.
    Its value is (("America/Los_Angeles" "Seattle")
     ("America/New_York" "New York")
     ("Europe/London" "London")
     ("Europe/Paris" "Paris")
     ("Asia/Calcutta" "Bangalore")
     ("Asia/Tokyo" "Tokyo"))

    Documentation:
    Alist of zoneinfo-style time zones and places for ‘display-time-world’.
    Each element has the form (TIMEZONE LABEL).
    TIMEZONE should be a string of the form AREA/LOCATION, where AREA is
    the name of a region -- a continent or ocean, and LOCATION is the name
    of a specific location, e.g., a city, within that region.
    LABEL is a string to display as the label of that TIMEZONE’s time.

But these values are _places_ not time zones. I'm wondering how, for
example, one would add UTC to the list?

Re: How to use display-time-world to show time in specific time zones?

[Emanuel Berg]

nljlistbox2@gmail.com (N. Jackson) writes:

> I'm wondering how to use display-time-world to
> display the time in specific time zones.
>
> The doc string for zoneinfo-style-world-list, which
> IIUC is the list of time zones used by
> display-time-world says:
>
> zoneinfo-style-world-list is a variable defined in
> ‘time.el’. Its value is (("America/Los_Angeles"
> "Seattle") ("America/New_York" "New York")
> ("Europe/London" "London") ("Europe/Paris" "Paris")
> ("Asia/Calcutta" "Bangalore") ("Asia/Tokyo"
> "Tokyo"))
>
> Documentation: Alist of zoneinfo-style time zones
> and places for ‘display-time-world’. Each element
> has the form (TIMEZONE LABEL). TIMEZONE should be
> a string of the form AREA/LOCATION, where AREA is
> the name of a region -- a continent or ocean, and
> LOCATION is the name of a specific location, e.g.,
> a city, within that region. LABEL is a string to
> display as the label of that TIMEZONE’s time.
>
> But these values are _places_ not time zones.

Do you mean there is another, more correct or
scientific notation for designating time zones?
Here the notation is "Area/Location". Are you unhappy
with that?

> I'm wondering how, for example, one would add UTC to
> the list?

Try add Greenland (Danmarkshavn) or Iceland because
they use GMT/UTC all year. (GMT and UTC are +0000.)

The Britton - which you have in your list already as

    ("Europe/London" "London")

- also use GMT in the winter but BST in the summer
(British Summer Time, or +0100).

--
underground experts united
http://user.it.uu.se/~embe8573

Re: How to use display-time-world to show time in specific time zones?

[Yuri Khan]

On Sat, Feb 20, 2016 at 11:13 PM, N. Jackson <nljlistbox2@gmail.com> wrote:

>     TIMEZONE should be a string of the form AREA/LOCATION, where AREA is
>     the name of a region -- a continent or ocean, and LOCATION is the name
>     of a specific location, e.g., a city, within that region.
>     LABEL is a string to display as the label of that TIMEZONE’s time.
>
> But these values are _places_ not time zones. I'm wondering how, for
> example, one would add UTC to the list?

This paragraph of documentation is very similar to the documentation
on the Olson timezone database:

ftp://ftp.iana.org/tz/data/Theory

    Names normally have the form AREA/LOCATION, where AREA is the name
    of a continent or ocean, and LOCATION is the name of a specific
    location within that region.  North and South America share the same
    area, 'America'.  Typical names are 'Africa/Cairo', 'America/New_York',
    and 'Pacific/Honolulu'.

This strongly indicates that zoneinfo-style-world-list just refers to
timezone names as listed in that database.

Armed with this knowledge, you can try using "Etc/UTC", and browse the
database for names of other time zones.