Yealink T4X phones in UTC+2 (SAST, CAT) timezone [bis]

[ghalse]

Earlier in the year I posted about problems setting Yealink T4X phones to use Central Africa Time (CAT, UTC+2) or South African Standard Time (SAST, also UTC+2). The response correctly pointed out that the issue in the Yealink template had been resolved as of V16.

I'm now running V16 - 16.0.910 on Linux to be exact - and the problem still (partly) persists. Our instance of 3CX has its timezone set to "+02:00 Central Africa Time" and the underlying Linux install also uses CAT as its timezone. If I deploy a Yealink phone using the standard yealinkT4x template as at version 89556, my phones do not display the right time.

Some experimentation has shown that if the extension's provisioning is set to "Use global Timezone" then the Yealink phone's timezone is set to a timezone of UTC+2 but the location defaults to "Estonia(Tallinn)" which has different DST rules to CAT. However, if I explicitly change the time zone for each extension to "GMT+2 Central Africa Time (no DST)" then the phones provision with the correct timezone and the time is correct.

Digging even deeper it looks like setting the global timezone to "+02:00 Central Africa Time" still sets TIME_TIMEZONE_YEALINK parameter to "GMT+2 Estonia(Tallinn)". Changing the parameter to match the "GMT+2 Central Africa Time (no DST)" string in the template makes things work as expected, at least as long as nothing reverts it.

 

[AWS2P]

If TMZ setting is sent wrongly from PBX you should reverts in max 24h with auto provision

 

[ghalse]

It turns out there is also a similar problem with the Yealink W60B DECT base station, except in that (at least in the case of version 89556 of the yealink.W60B.fxs.xml template) there's no option to select the correct timezone. The same is true of the W52P and W56P DECT phones.

The W60B (firmware version 77.83.0.65) itself correctly supports the CAT timezone:



but there is simply no way to set this with the stock template. It can readily be fixed by editing the template to add:

<option value="+2" displaytext="+02:00 Central Africa Time" id="120" zone="2:00">
  <item name="TimeZoneName">Harare</item>
</option>

but that obviously takes you out of support.

This leaves no option but to use the hack suggested by @3C Technology: use the "GMT+2 Russia(Kaliningrad)" timezone as a workaround. That works so long as Russia doesn't change things (again).

Since it isn't obvious to people in Africa which European timezones might coincidentally match their own, I'm posting this in the hopes that it helps someone else searching for a solution in future. It would of course be nice if it was fixed too