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E:\Working\Brother_Education\Preparatory_Stage_Maths-3_(11-09-2024)\Open_Files\CHAP_10
\ 06-Jan-2024 Sonia Suyal Proof-1 Reader’s Sign _______________________ Date __________
24-Hour CloCk
We know that a day has 24 hours. The hour 2400 hours
or
0000 hours
2300 hours
hand takes 2 rounds of the clock to cover 24 2200 hours 11 12 1 0100 hours
0200 hours
hours. We use a.m. (ante meridiem) for the time 2100 hours 9 10 midnight 2 3 0300 hours
from 12 midnight to 12 noon and p.m. (post 2000 hours 8 4 0400 hours
meridiem) is used for the time from 12 noon 1900 hours 7 5 0500 hours
to 12 midnight. 1800 hours 6 p.m. a.m. 6 0600 hours
1700 hours 5 7 0700 hours
We commonly use 12-hour clock to see the 4 8
1600 hours 0800 hours
time. But railways, airlines and armed forces use 1500 hours 3 2 noon 10 9 0900 hours
24-hour clock to read and tell time. 1400 hours 1 12 11 1000 hours
1300 hours 1200 hours 1100 hours
Look at the clocks shown below.
11 12 1 Note
10 2 analog The 24-hour clock
20:00 9 8 4 3 clock does not use a.m. or
p.m. to show the time.
digital clock 7 6 5
Both clocks show the same time, that is, 8 o’clock at night. The digital clock shows the
time in 24-hour clock in the form hh:mm. The first two digits in 24-hour clock show hours
and the last two digits show minutes.
In 24-hour clock, 12 midnight is denoted as 00:00 hours or as 24:00 hours.
time (in hours and minutes)
24-hour 12-hour 24-hour 12-hour
0000/00:00 hours 12 midnight 1200/12:00 hours 12 noon
0100/01:00 hours 1:00 a.m. 1300/13:00 hours 1:00 p.m.
0200/02:00 hours 2:00 a.m. 1400/14:00 hours 2:00 p.m.
0300/03:00 hours 3:00 a.m. 1500/15:00 hours 3:00 p.m.
0400/04:00 hours 4:00 a.m. 1600/16:00 hours 4:00 p.m.
0500/05:00 hours 5:00 a.m. 1700/17:00 hours 5:00 p.m.
0600/06:00 hours 6:00 a.m. 1800/18:00 hours 6:00 p.m.
0700/07:00 hours 7:00 a.m. 1900/19:00 hours 7:00 p.m.
0800/08:00 hours 8:00 a.m. 2000/20:00 hours 8:00 p.m.
0900/09:00 hours 9:00 a.m. 2100/21:00 hours 9:00 p.m.
1000/10:00 hours 10:00 a.m. 2200/22:00 hours 10:00 p.m.
1100/11:00 hours 11:00 a.m. 2300/23:00 hours 11:00 p.m.
178 Mathematics-3
