"Time when mail file's file system was recorded to be down.
If that file system seems to be up, the value is nil.")
-(defcustom display-time-world-list
+(defcustom zoneinfo-style-world-list
'(("America/Los_Angeles" "Seattle")
("America/New_York" "New York")
("Europe/London" "London")
("Europe/Paris" "Paris")
("Asia/Calcutta" "Bangalore")
("Asia/Tokyo" "Tokyo"))
- "Alist specifying time zones and places for `display-time-world'.
+ "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."
+ :group 'display-time
+ :type '(repeat (list string string))
+ :version "23.1")
+
+(defcustom legacy-style-world-list
+ '(("PST8PDT" "Seattle")
+ ("EST5EDT" "New York")
+ ("BST0BDT" "London")
+ ("CET-1CDT" "Paris")
+ ("IST-5:30IDT" "Bangalore")
+ ("JST-9JDT" "Tokyo"))
+ "Alist of traditional-style time zones and places for `display-time-world'.
+Each element has the form (TIMEZONE LABEL).
+TIMEZONE should be a string of the form:
+
+ std[+|-]offset[dst[offset][,date[/time],date[/time]]]
+
+See the documentation of the TZ environment variable on your system,
+for more details about the format of TIMEZONE.
+LABEL is a string to display as the label of that TIMEZONE's time."
+ :group 'display-time
+ :type '(repeat (list string string))
+ :version "23.1")
+
+(defcustom display-time-world-list
+ (if (memq 'system-type '(gnu/linux ms-dos))
+ zoneinfo-style-world-list
+ legacy-style-world-list)
+ "Alist of time zones and places for `display-time-world' to display.
Each element has the form (TIMEZONE LABEL).
-TIMEZONE should be a valid argument for `set-time-zone-rule'.
-LABEL is a string to display to label that zone's time."
+TIMEZONE should be in the format supported by `set-time-zone-rule' on
+your system. See the documentation of `zoneinfo-style-world-list' and
+\`legacy-style-world-list' for two widely used formats.
+LABEL is a string to display as the label of that TIMEZONE's time."
:group 'display-time
:type '(repeat (list string string))
:version "23.1")