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E:\Working\Brother_Education\Preparatory_Stage_Maths-4\Open_Files\Chap-12
\\October 31, 2023 4:02 PM Bharat Arora P-5 Reader _________________________ Date: ___________________

For example: 0750 hours = 7:50 a.m. Note

1057 hours = 10:57 a.m. a.m. stands for ante meridiem.
p.m. stands for post meridiem.
rule 2: If 24-hour clock time is greater than 1200

hours, then subtract 1200 hours from the given time. Separate the hours and
minutes with colon. Write p.m. next to it.

For example:

(a) 1300 hours = 1:00 p.m. FACTS

2400 hours or 0000 hours
( 1300 hours – 1200 hours = 0100 hours) = 12:00 midnight
( 2400 hours – 1200 hours
(b) 2359 hours = 11:59 p.m. = 1200 hours)

( 2359 hours – 1200 hours = 1159 hours)

converting the 12-hour clock time to 24-hour clock time

rule 1: For the time from 1:00 a.m. to 12:59 p.m., do not change the number. Write

the time without colon (:) sign and instead of a.m. or p.m. write hours.
For example:

(a) 2:00 a.m. = 0200 hours (b) 11:38 a.m. = 1138 hours

(c) 12 noon = 1200 hours (d) 12:58 p.m. = 1258 hours

rule 2: For the time from 1:00 p.m. to 11:59 p.m., add 12:00 hours and write hours

instead of p.m.

For example:

(a) 4:30 p.m. = 1630 hours ( 1200 hours + 0430 hours = 1630 hours)

(b) 9:00 p.m. = 2100 hours ( 1200 hours + 0900 hours = 2100 hours)

rule 3: For the time from 12 midnight to 12:59 a.m., subtract 12:00 hours and write
the time with hours instead of a.m.

For example:

(a) 12:30 a.m. = 0030 hours ( 1230 hours – 1200 hours = 0030 hours)

(b) 12:59 a.m. = 0059 hours ( 1259 hours – 1200 hours = 0059 hours)

teacher’s
tip Explain to the children that if the 24-hour clock time is in between 1200 hours and 2359 hours then it is
written with p.m. and separate the hours and minutes with colon.

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