FYI I received the following information from TP-Link based on the support ticket that I opened earlier this week:

TP-Link:

"​Our R&D have informed us that the time function will work as normal after the 1st of November."

So things should be back OK soon.

Same issue... mix of HS110 v1 and v2, also some HS110 v4.  Older devices have the issue.

timezone is correct for HS110v4 but all others seems to add summer time to any of the UTC+1 values.  If I set GMT/UTC = 0, the time is correct over all devices.

correcting the time zone to Europe/Stockholm (+1) they are all different causing stuff to turn off 1hour early.

First time this time change hasn't followed Summer/Winter time.  Hope for firmware fix soon since the app update today didn't fix it.

FYI

The time on my devices is correct again when setting my local timezone.

Same, now correct but a few weeks it's been wrong.  

Seems Sunmer Time change values are set to America standards :( (aka the time zones are pointless and wrong in the firmware)

It would be nice that each device has its own "summer time/daylight savings" setting.  At least let us manually switch it (auto/on/off) since ST changes all the time around the world.

daylight savings mode idea...

auto = follows the timezone summertime values set by TPLink within the device firmware.

on = manual +1hour modifier on UTC timezone (summer time)

off = manual no modification of UTC timezone.

Then all the time zones changes wouldn't be wrong and TPLink do not need to worry about this changing dates in the firmware for older devices for ALL units.

so please TPLink, one more firmware to fix for older devices + the new ones too (v2/3/4 etc).  I don't want these old working units to become e-waste.

@FAZZA 

how fo I actually change the time 

@VinnyIreland1 

The only way I know to set time values is in the Kasa app.

KASA --> menu (top left 3 horizontal lines) --> Settings --> Location and Time...

You can then set both a "Time Zone" and when you tap on "Location" the next screen is a "Sync Location" button.

Pressing this syncs time to all KASA devices.

You can find this same info with screenshots here: https://www.tp-link.com/us/support/faq/1481/