Time Zone DST for 27P and 29G in US not correct.

[mjradik]

So I'm new to Yealink, and decided to use the T-27P and T-29G phones exclusively. Great phones so far, but I noticed it is not calculating Day light savings time correctly in the United States. It is making the time on the phone off by 1 hour. In doing searches, I've seen people with these problems going back to 2013, with may different types of phones. I'm using the latest x.80.0.25 firmware files.

If I set the time zone to:
local_time.time_zone = -5
local_time.time_zone_name = US-Eastern Time
local_time.summer_time = 2

The time is 1 hour early (Like it is not applying DST). The DST mode is set to automatic. However, If I change the Time zone to Bahamas(Nassau), it sets the time/DST correctly. Bahamas(Nassau) and US-Eastern have the same DST settings.

I also notice if I set the time zone to "Canada-Manitoba(Winnipeg)" for Central, "Canada(Edmonton,Calgary)" for Mountain, and "Canada(Edmonton,Calgary)" for Pacific, it sets the time correctly.

I know I'm not the only one with this issue. Can't Yealink get their Time zones correct?

[mjradik]

So after some further investigation, I found some stuff out. I'm looking at the default autodst.xml file yealink provides. I see the following two entries.
<DST szTime="-5" szZone="Bahamas(Nassau)" iType="1" szStart="3/2/7/2" szEnd="11/1/7/2" szOffset="60"/>
<DST szTime="-5" szZone="United States-Eastern Time" iType="1" szStart="3/2/7/2" szEnd="11/1/7/2" szOffset="60"/>

With the exception of the name they are exactly the same. I also notice the documentation for the T2x phones, it says to use "US-Eastern Time" where the above says "United States-Eastern Time". So I decided to try to use "United States-Eastern Time" in the config file, but the config file doesn't like that. Its needs to be "US-Eastern Time" I even tried to change the .xml file to read "US-Eastern Time" but it still does not apply the DST and is off by 1 hour. Just doesn't make any sense to me why yealink doesn't auto calculate USA DST properly. If I manually set the start and end times of DST on the config file it works, but if I set the summer time to auto, it doesn't.

[Flora_Yealink]

Yes, you are right, the 25 version has the issue , please upgrade to the latest version
T29: 46.80.0.35.rom

T27: 45.80.0.35.rom

you can use below syntax.
#!version:1.0.0.1

local_time.time_zone = -5
local_time.time_zone_name = United States-Eastern Time
local_time.summer_time = 2

Best Regards!
Flora