Google calendar is 1 hour out on some devices

[TwistedHelixis]

Our public calendar is apparently 1 hour out for a few users when they look at dates after October (after DST). All the dates are fine for me (phone and laptop) so I originally assumed it's a local device issue. I have asked someone with the issue (iPhone) to check their date / time settings and they are set to auto. I have also checked the calendar settings and they are set to GMT +00:00

 

So I am a bit lost. Any ideas?

[TwistedHelixis]

Just been told that the office have just changed the time zone from GMT+1 UK to GMT +00:00, but it still is not correct on those same devices.

 

 

Edited September 25, 2018 by TwistedHelixis