If you do it by the time on the clock it’s like landscape lighting that you have to adjust every three to four weeks.I think a better, and more simple option, would be to have the option to have automatically change picture modes by the time on the clock. Say at 7pm it switches to isf dark and at 7am it switches back to isf bright. That way when you turn on the tv at day/night it's in the right mode for you.
To make it less of a hassle, you would have to know the time zone where the TV is installed and use sunrise/sunset data to change the settings dynamically.
Sounds like a job for IFTTT.