24-hour clock
You learn to read a 24-hour clock, like 19:00, and say which part of the day it is.
How to work it out
- If the hour is greater than 12, subtract 12: 19:00 is 7 o’clock.
- State the part of the day.
A worked example
15:00
- Look at the hour: 15 is more than 12.
- Subtract 12: 15 − 12 = 3.
- It is 3 o'clock in the afternoon.
More examples
21:00
- Look at the hour: 21 is more than 12.
- Subtract 12: 21 − 12 = 9.
- It is 9 o'clock in the evening.
09:00
- Look at the hour: 9 is not more than 12, so nothing changes.
- It is 9 o'clock in the morning.
Try it yourself
What time is that on an analogue clock?
16:00 =
What time is that on an analogue clock?
22:00 =
Watch out
You subtract 10 instead of 12: 19:00 becomes 9 o'clock.
An analogue clock has 12 hours. Always subtract 12: 19 − 12 = 7.
You forget which part of the day it is: 21:00 and 09:00 are both 9 o'clock.
Say whether it is morning or evening. From 18:00 it is evening.
Tips
- From 13:00 you subtract 12.
Exceptions
- 12:00 stays 12 o'clock, and 00:00 is midnight.
Why it works
A clock with hands goes round twice a day, so it only counts to 12. A digital clock counts all day, to 24. After 12 noon you subtract 12 to find the time on an analogue clock.