Usually the sign-in wizard show below will only appear if the Phone is not receiving a DHCP GMT Offset.

Once added as DHCP Option 2 to the DHCP Server scope (example for London 0x00000001) the phone no longer prompts for the above.
The below shown are the additional actions when pressing next:



Another option can be using the attached configuration:
<test device.set="1"
device.lync.timeZone.set="1"
device.lync.timeZone="0" />
Download, unzip and import via Utilities > Import & Export Configuration > Import Configuration
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The title Polycom Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. My official "day" Job is 3rd Level support at Poly but I am unable to provide official support via the community.
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Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's