The number on the clock has military time because of the 24 hours, showing each hour of the day.
It doesn't show the a.m. as 1:00 to 12:00 which is 1 am to 12 pm. It is known as 0100 for 1 am.
But it does show 13 to 24 which is known as 1 a.m. to 12 p.m.
The initials in the star points to the organ that will possibly be affected, twelve hours later.
A1 to A12
B1-B12
C1-C12
D17-D22