Interesting. I propose that the transition between AM and PM should happen right in the human-sensible middle of the day. If most people start their daily activity around 6, and retire by by 10pm, then the middle would be 14hrs.
This would also give a nice 3-part division to the day that matches their use: 1st 8 hours for the morning, next 8 hours for the afternoon, and the next 8 hours for evening/night. Currently, morning alone is 12 hours, and afternoon is like 6 (or less) and the evening takes the rest.
But I guess the current noon time is chosen for when the sun is highest in the sky, so maybe to preserve noon as the transition point, morning should start from 4:00 hrs, then the afternoon starts from 12:00 hours, and evening would start from 20:00 hours.
This would also give a nice 3-part division to the day that matches their use: 1st 8 hours for the morning, next 8 hours for the afternoon, and the next 8 hours for evening/night. Currently, morning alone is 12 hours, and afternoon is like 6 (or less) and the evening takes the rest.
But I guess the current noon time is chosen for when the sun is highest in the sky, so maybe to preserve noon as the transition point, morning should start from 4:00 hrs, then the afternoon starts from 12:00 hours, and evening would start from 20:00 hours.