Page 236 - New Medley 5 Semester 1

Let us see the time on the two clocks.

12-hour 24-hour 24-hour 12-hour

12 midnight 0000 hours 1200 hours 12 noon
2:00 a.m. 0200 hours 1330 hours 1:30 p.m.

3:15 a.m. 0315 hours 1845 hours 6:45 p.m.

8:30 a.m. 0830 hours 2000 hours 8:00 p.m.

11:55 a.m. 1155 hours 2259 hours 10:59 p.m.

Conversion of Time on the Two Systems

To convert timings greater than 12 hours on 24-hour clock into 12-hour

clock, we subtract 12 from hours and write the time in p.m. using two
dots(:). Less than 12 hours time is expressed in a.m.

Examples: 0835 hours mean 8:35 a.m.

2015 hours mean 8:15 p.m. (20 – 12 = 8)

Again, the timings given on 12-hour clock are expressed in four digits
adding hours to them. Time in a.m. is directly written in 4 digits for 24-
hour clock but when time in p.m. is expressed on 24-hour clock, we add 12

to the number of hours.

Examples: 6:10 a.m. means 0610 hours.

6:10 p.m. means 1810 hours, (6 + 12 = 18)

EXERCISE 7.1

A. Express the following on 12-hour clock.

1. 0940 hours 2. 1615 hours 3. 2400 hours

4. 0705 hours 5. 2120 hours 6. 1130 hours

B. Express the following on 24-hour clock.
1. 3:05 a.m. 2. 6:45 p.m. 3. 8:30 a.m.

4. 12 noon 5. 12 midnight 6. 7:25 p.m.

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