My hub has started showing time with exactly 1 hour ahead of the correct local time. I suspect tzdata in the system may be obsolete or something. To solve the problem caused by this issue, I have manually changed the Time Zone information under settings, to a time zone that is 1 hour behind my local time zone, which assures time based rules run at correct time.
I live in the south east of Brazil and time zone should be set as America/Sao_Paulo. Please note that we are currently under BRST time (no daylight savings time) rule.
Since my system apparently thinks we are under daylight savings time rule, I temporarily had to change my time zone to America/Buenos_Aires. It fixes the problem, but I think the correct way to fix is to deploy an update tzdata file.
You may want to provide examples / details of exactly where in the HE interface you are seeing the different time. I'm not doubting you are seeing it, just it will help the developers zero in on what the issue may be.
My correct timezone is America/Sao_Paulo. Yes, I can update time from browser and it becomes correct for a while. But something makes it move 1 hour forward. I'm not sure when (after midnight?)/what system service is causing this... Screen grab below shows correct time in system, after I clicked the Update from browser button.
Make sure your Lat/Long are correct and also you can check what your NTP server is set to using: your.hub.ip/hub/advanced/ntpServer
According to Google, your time zone you have set is Brazilian Standard Time, which is GMT -3, Current time is 2:21PM (14:21), so the time in your screenshot looks correct for when you posted it. Not sure if that is from your forcing the browser time or not?
If you have a local NTP server (your router may act as one) you can force the hub to use that or anything else you wish:
EDIT: After reading your first post again (fully), it does almost sound like the hub itself is wrongly converting the info from the NTP server even thought it shows it should be converting it to BRST.
Thanks for this info.
Is there also a command to check which time server it's using now?
I tried issuing the command without the last part (in your example time.google.com) to see if it would show me the current time server it is using, but it only returned the string serverName
Has to be /hub/advanced/ntpServer without the trailing slash to view it. If it is showing you 'serverName' maybe you accidentally set it to that by mistake at the first attempt.
So, I guess we now know that the system time is changing whenever (daily maintenance routines?) contact the defined time server. What do you think?
Second EDIT: for information, the ntp.org time servers available to be used in my location are:
a.ntp.br
b.ntp.br
c.ntp.br
gps.ntp.br
a.st1.ntp.br
b.st1.ntp.br
c.st1.ntp.br
d.st1.ntp.br
According to information obtained at https://ntp.br.
The same page (in Portuguese) mentions that (translated to English by google translate):
"DST
Did your device advance or delay 1h by itself? The use of daylight saving time in Brazil was ended by decree 9,772 of April 26, 2019. NTP always works on the UTC scale and is not affected by the change, nor does it interfere with time zone or daylight saving time adjustments. The treatment of local time and daylight saving time are functions of the Operating Systems (Windows, Android, IOS, Linux, BSDs, Mac OS, etc). Your device's Operating System must be up to date and correctly configured to avoid undue time zone changes."
Third EDIT: I manually pressed the update from browser button to have correct it again, and will await until tomorrow to verify date/time again to see if time has advanced on hour again overnight.
It sounds like a Hubitat software issue, since Iām assuming (perhaps wrongly ) that prior to 2019 your clocks would have sprung ahead at this time. @support_team
Yes, it's probably caused by obsolete tzdata, as every time the system pulls data from the defined time server, it wrongly advances one hour, which probably means tzdata thinks we are currently under daylight savings time, but we are not (see my post 8 above about decree establishing that Brasil will not be using daylight savings time anymore).
Jumping here to share that I'm facing the same issue. Hub time 1 hour ahead, timezone is the same America/Sao paulo. Lat/Lon are spot on, this is not the cause. Pertaining to DST, Cesar is correct and it is not in use these days, but stay sharp because it may return next year with the next president. Letting the user define whether to apply DST or not may be a good idea.
) that prior to 2019 your clocks would have sprung ahead at this time. 
