timeZoneList(...)

The time zone list is a named list whose names are the character strings that are recognized when you convert strings to time objects, and whose elements are the corresponding time zone objects. (See the documentation for class timeZone.) The timeZoneList function provides an easy way for the user to define the character strings to use for input of given time zones, and to define user-defined time zones for use in timeDate objects. For example, a North American user would probably want to recognize "EST" as the US or Canadian time zone known as Eastern Standard Time, whereas an Australian user might prefer to have "EST" refer to Eastern Australian time. The timeZoneList function has the following behavior:

• If no arguments are given, the current time zone list is returned.
• If a single list is given as the argument, its named components are added to the time zone list.
• If multiple named arguments are given, they are added to the list.

In either of the two latter cases, the elements to be added to the list must be time zone objects. The default time zone list has the following built-in zone components. (See documentation on the timeZone class for more information.)

# return the entire time zone list 
timeZoneList() 
# define the string "PDT8PST" to mean US Pacific time 
timeZoneList(PDT8PST = timeZoneC("us/pacific")) 
# define a time zone for a small island 1/2 hour east of GMT 
timeZoneList(small.island = timeZoneR(offset=1800))