Bishop Kenny NJROTC NS1Lesson 24 Hour Clock

1. The 24-hour Clock

2. The military does not measure time by
the standard 12-hour clock. It uses the
24-hour clock.

3. A 12-hour clock
uses numbers
from 1 to 12
followed by a.m.
or p.m. to identify
each of the 24
hours in a day.
What does a.m. and p.m. stand for?

4. What does a.m. and
p.m. stand for?
a.m. — ANTE MERIDIEM, or before
noon
p.m. — POST MERIDIEM, or afternoon

5. The military uses the 24-hour clock, which
uses the numbers 0000 through 2400.
Under this system, midnight is 0000 or 2400,
1 a.m. is 0100, 1 p.m. is 1300, and so on.

6. Because a unique number designates
each hour, there is no need to follow it
by a.m. or p.m.

7. Military Time
• Based on a
24-hour time
standard
What is the military time above, both
a.m. and p.m.?

8. Military Time
• Based on a
24-hour time
standard
What is the military time above, both
a.m. and p.m.?
0301 or 1501

9. Standard Time vs. Military Time
Midnight = 0000 or 2400
1:00 a.m. = 0100
2:00 a.m. = 0200
3:00 a.m. = 0300
4:00 a.m. = 0400
5:00 a.m. = 0500
6:00 a.m. = 0600
7:00 a.m. = 0700
8:00 a.m. = 0800
9:00 a.m. = 0900
10:00 a.m. = 1000
11:00 a.m. = 1100

10. Standard Time vs. Military Time
Noon = 1200
1:00 p.m. = 1300
2:00 p.m. = 1400
3:00 p.m. = 1500
4:00 p.m. = 1600
5:00 p.m. = 1700
6:00 p.m. = 1800
7:00 p.m. = 1900
8:00 p.m. = 2000
9:00 p.m. = 2100
10:00 p.m. = 2200
11:00 p.m. = 2300

11. What about Military
Minutes?
Minutes are measured the same way in military
time as they are in standard time, using the
numbers 01 to 59.
Example: 11:45 p.m. standard time would
be written 2345 military time.

12. Why is midnight
0000 and not 2400?
Sometimes with the military and emergency
services personnel midnight is expressed
both ways.

13. Military time is always expressed in hours
and minutes without a colon and add the
word “hours” afterward.
Example: 0301 hours

14. When military time needs to be expressed
down to the second, you insert a colon
between the minutes and seconds.
Example: 0301:38 hours

15. What time would it be on the 24-hour
clock for the following times?
A. 7:00 a.m.
B. 12:30 p.m.
C. 6:50 p.m.
D. 9:15 p.m.
E. Midnight

16. What time would it be on the 24-hour
clock for the following times?
A. 7:00 a.m. 0700 hours
B. 12:30 p.m. 1230 hours
C. 6:50 p.m. 1850 hours
D. 9:15 p.m. 2115 hours
E. Midnight 0000 or 2400 hours

17. Conclusion
Learning how to convert standard time to
military time will greatly benefit you when
on base and ship visits.