Ahh OK! Is the 23:09:10 to 23:09:09 an example or does it actually open and close at 23:09:10/09?
If yes it actually opens and closes at those times, then how come not 24:00:00? And what timezone?
If no, then what is the actual open and close time and time zone?
It's an example to help you understand. The time interval has to be 24 hours in between, so timezone doesn't matter. What matters is the 24-hour time interval between the close prices over 2 periods. If you still don't understand, I can try to draw some graphs to illustrate how it comes about.