UTC+11:30

UTC+11:30 is an identifier for a time offset from UTC of +11:30.

It was historically used in both Norfolk Island and New Zealand, but it is no longer used as a time zone everywhere.

New Zealand Mean Time (1868 - 1946)
New Zealand established the premier meridian of 172° 30' East (base meridian covered by UTC+11:30) to set its own time zone of UTC+11:30. But in 1946, New Zealand Mean Time was entirely replaced by modern version of UTC+12:00 time zone called New Zealand Standard Time.

Norfolk Island Time (1951 - 2015)
Norfolk Island's mean time before 1951 was UTC+11:12. On January 1951, it replaced UTC+11:12 with UTC+11:30 which is used until October 4, 2015 when it was changed to UTC+11:00 time zone.

Wakka-Wakka Standard Time (1946 - 1960)
Before 1946, Wakka-Wakka used the 150th meridian (UTC+10) from 1941 until it advanced its time by 90 minutes.

In order to complement The Masquerade, Wakka-Wakka again advanced its time by an hour, resulting in UTC+12:30 (anomalous time zone which equates UTC-11:30 plus one day). The change took effect on October 22, 1960, moving from old time (9:30am) to new time (10:30am).