Updated to add device.set="1" like so:
<DEVICE_SETTINGS device.set="1" device.sntp.serverName="pool.ntp.org" device.sntp.gmtOffset="-28800" device.auth.localAdminPassword.set="1" device.auth.localAdminPassword="" /><SNTP tcpIpApp.sntp.resyncPeriod="86400" tcpIpApp.sntp.address="198.202.199.1" tcpIpApp.sntp.gmtOffset.overrideDHCP="0" tcpIpApp.sntp.gmtOffset="-28800" tcpIpApp.sntp.daylightSavings.enable="1" tcpIpApp.sntp.daylightSavings.fixedDayEnable="0" tcpIpApp.sntp.daylightSavings.start.month="3" tcpIpApp.sntp.daylightSavings.start.date="13" tcpIpApp.sntp.daylightSavings.start.time="2" tcpIpApp.sntp.daylightSavings.start.dayOfWeek="1" tcpIpApp.sntp.daylightSavings.start.dayOfWeek.lastInMonth="0" tcpIpApp.sntp.daylightSavings.stop.month="11" tcpIpApp.sntp.daylightSavings.stop.date="6" tcpIpApp.sntp.daylightSavings.stop.time="2" tcpIpApp.sntp.daylightSavings.stop.dayOfWeek="0" tcpIpApp.sntp.daylightSavings.stop.dayOfWeek.lastInMonth="0" />
The exported config from the phone is:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?><!-- Application SIP Mink 4.0.11.0583 21-Jun-16 16:56 --><!-- Created 14-03-2017 08:45 --><PHONE_CONFIG><!-- Note: The following parameters have been excluded from the export: reg.1.auth.password="" reg.2.auth.password="" reg.3.auth.password="" --><ALL attendant.behaviors.display.spontaneousCallAppearances.automata="1" attendant.behaviors.display.spontaneousCallAppearances.normal="0" device.auth.localAdminPassword.set="1" device.set="1" device.sntp.gmtOffset="-28800" device.sntp.serverName="pool.ntp.org" dialplan.digitmap="[2-9]11|0x.T|1[0-1]x|1[2-9]xxxxxxxxx|[2-9]xxxxxx" feature.enhancedFeatureKeys.enabled="1" ptt.pageMode.displayName="Matthew Office" ptt.pageMode.enable="1" softkey.feature.forward="0" softkey.feature.newcall="0" tcpIpApp.sntp.address="198.202.199.1" tcpIpApp.sntp.daylightSavings.start.date="13" tcpIpApp.sntp.daylightSavings.stop.date="6" tcpIpApp.sntp.gmtOffset="-28800" voice.volume.persist.handset="1" voIpProt.SIP.specialEvent.checkSync.alwaysReboot="1" reg.1.address="96771" reg.2.address="93435" reg.3.address="100" reg.1.auth.userId="96771" reg.2.auth.userId="93435" reg.3.auth.userId="100" reg.1.displayName="6771-Matthew Office" reg.2.displayName="3435-Matthew Office" reg.3.displayName="100-Matthew Office" reg.1.label="426-6771" reg.2.label="469-3435" reg.3.label="100" reg.1.lineKeys="2" reg.2.lineKeys="2" reg.3.lineKeys="2" reg.1.outboundProxy.port="5060" reg.2.outboundProxy.port="5060" reg.3.outboundProxy.port="5060" reg.1.outboundProxy.transport="TCPOnly" reg.2.outboundProxy.transport="TCPOnly" reg.3.outboundProxy.transport="TCPOnly" reg.1.ringType="2" reg.2.ringType="4" reg.3.ringType="7" reg.1.type="shared" reg.2.type="shared" softkey.1.action="$FPage$$FPage$" softkey.2.action="$FPage$$FPage$" softkey.1.enable="1" softkey.2.enable="1" softkey.1.insert="2" softkey.1.label="Page" softkey.2.label="Page" softkey.1.use.dialtone="1" softkey.2.use.hold="1" reg.1.server.1.address="10.10.155.8" reg.2.server.1.address="10.10.155.8" reg.3.server.1.address="10.10.155.8" reg.1.server.1.expires="80" reg.2.server.1.expires="80" reg.3.server.1.expires="80" reg.1.server.1.transport="TCPOnly" reg.2.server.1.transport="TCPOnly" reg.3.server.1.transport="TCPOnly" /></PHONE_CONFIG>
Still showing standard time.