iPhone Display settings change on its own?

[cSalmon]

iPhone 8+ iOS 13.7. For the past week or so I open up the phone and it‘s Display settings have changed to dark mode. I haven’t done this and need to change it back to light. At first I thought it must be user error, getting jostled in a bag or such, but now it has happened more than four times. This past time it sat on the desk and in the morning was once again in dark mode.
Anyone have suggestions on how to fix this?

thanks

ps. Live alone so not a prankster

 

[eyet]

You’ve probably already checked this, but is the automatic option set to “light until sunset” or “custom schedule”?

Also, is the correct time zone set in Settings -> General -> Date & Time?

 

[cSalmon]

Thanks for your suggestions, I will change the date region from auto to my city. The Setting switch has happened a couple of times in the middle of the afternoon so I don’t think it’s the sunset-sunrise setting i do have it set to off auto

I appreciate your help, thanks