Cisco 8831 conference phone displaying incorrect time

i have an Asterisk server which about 15 Sip phones registered and working fine.

the only thing thats broken is that the cisco 8831 phone is showing incorrect time, its showing GMT time. all other cisco 7960 phones are showing the correct time.

. when i log into the web interface of the phone it shows the correct time zone, but its not showing the correct time. i have tried diffrent firmware for the 8831, and i have tried different ntp servers as well, i have tired diffrent Time zones, but still the time is still showing GMT time.

Below is the xml extract from the 8831 XML file. (i have replaced the < > with # in the output below, only for this forum.)

#dateTimeSetting#
#dateTemplate#D/M/Y#/dateTemplate#
#timeZone#Central Europe Standard/Daylight Time#/timeZone#
#ntps#
#ntp#
#name#{$network_time_server}#/name#
#ntpMode#Unicast#/ntpMode#
#/ntp#
#/ntps#
#/dateTimeSetting#

Below is part of the core log files output from the phone

0850 NOT 14:09:54.750251 Feb 3 14:09:54 JAVA: configmgr MQThread|cip.cfg.TimeDateProperty:? - setTimeZone tz:Arabian Standard Time ctz:Asia/Muscat
0851 NOT 14:09:54.775169 Feb 3 14:09:54 JAVA: *** SetTimezone *** :TZ=GMT-0
0852 NOT 14:09:54.783064 Feb 3 14:09:54 JAVA: getenv TZ::GMT-0

Try the “Preformatted text” button – it is three back-ticks to open/close, like this:

<dateTimeSetting>
</dateTimeSetting>

Is that the same value that works for you on your 7960s ?

Maybe try integers on the 8831 eg. +2 ?

i managed to get this working. i had to take the j9-tzdata.jar file from a Cisco CUCM server and uploaded it to my freepbx tftpboot folder and added the below text to the phones xml file for it to start showing the correct time.

<tzdata>

<tzolsonversion>2017b</tzolsonversion>

<tzupdater>j9-tzdata.jar</tzupdater>

</tzdata>

<olsonTimeZone>Africa/Harare</olsonTimeZone>