About the American Time Form
What does "12:45 am" mean? Is it in the middle night or afternoon? I'm totally confused.
As in China, 00:00 is the start of a new day and 12:00 is noon.

Question

About the American Time Form
What does "12:45 am" mean?   Is it in the middle night or afternoon?  I'm totally confused.
As in China, 00:00 is the start of a new day and 12:00 is noon.

Answer

12AM = midnight.
12PM = midday

No confusions!

Answer

12:00pm is noon / lunchtime ......12:45pm is 45 minutes after 12:00pm (noon/lunchtime). 
 12:00am is midnight ..................12:45am is 45 minutes after 12:00am (midnight)