I was little perplexed because even to my eyes it seemed too dark due to the amount of light for 6:20 am from previous days (guess your body is far more in sync with time than Samsung can manage even with AI).
I then spied an analog clock and the truth was revealed it was actually 5:20am.
So I went to Date and Time settings on phone (S23 Ultra running One UI 6.1.1) and found that I had to manually switch time zone to Brisbane to fix problem and turn off Auto Time Zone feature in settings (refer attached screenshot). But this sucked as I travel occasionally overseas so obviously having Auto Time Zone on is helpful.
When I then went to turn back on Auto Time Zone it reverted back to 1 hr ahead...Not happy Jan .
So after a bit of 'googling' found the fix to this dilemma.
Step 1. Restart phone
Step 2. Toggle off and on "Automatic date and time".
Step 3. Toggle off and on "Automatic time zone".
Problem solved...Yay!
Realised this was the first Daylight Saving start date since I bought this phone (purchased the phone last November) and the automatic settings worked fine at the end of DST earlier this year but obviously failed at the start of DST now.
Interestingly Apple has no problem with start and ends of DST as my old Apple iPhone X has the correct time. Samsung needs to do better :(
