Yealink SIP-T23P User Manual page 149

Time Zone
+11:00 New Caledonia(Noumea)
+11:30 Norfolk Island
+12:00 New Zealand(Wellington, Auckland)
+12:45 New Zealand(Chatham Islands)
+13:00 Tonga(Nukualofa)
+13:30 Chatham Islands
+14:00 Kiribati
Appendix A-Time Zones
Time Zone Name
139