If you go to the main settings, you can set your timezone. Then when you connect to the lights you tap the time and update it and it shouls give you the correct time. There have been a couple of updates after I wrote the guide but the overall functionality remained the same, tho.
So try setting the timezone first, and then when you connect to the light tap the time (if the app doesn't ask you first) and you should be fine.The correct time might not should after you tap to correct it, but just close the app and open it again and the time at the top should be fine, then you can ignore the update time message if it shows again. I hope that helps.