The DISPLAY_TIMEZONEvariable specifies the time zone displayed in the site, which may be different from the time zone of the server on which the site is running.
The ID for a timezone can be either a full name such as "America/Los_Angeles", or a custom ID in the form GMT[+|-]hh[[:]mm] such as "GMT-08:00". It can also be in the form of a three letter abbreviation such as "PST".
The default timezone of the JVM, if it is undefined.