Time & timetables
Telling the time
You can tell the time on analogue and digital clocks, and use a.m., p.m. and the 24-hour clock so everyone knows exactly which time you mean.
a.m. and p.m.
The letters a.m. mean a time in the morning (from midnight to midday). The letters p.m. mean a time in the afternoon or evening (from midday to midnight). So 6.45 a.m. is early in the morning, and 6.45 p.m. is in the evening.
Analogue and digital clocks
An analogue clock has hands and two scales — one from midnight to midday and one from midday to midnight. A digital clock shows the time in numbers. A digital time of 13:26 is the same as 1.26 p.m.
The 24-hour clock
The 24-hour clock always uses four digits, such as 08:35 or 20:35. Morning times look the same (8.35 a.m. is 08:35). To change an afternoon or evening time, add 12 to the hours: 6.50 p.m. becomes 18:50, and 9 p.m. becomes 21:00.
Units of time
There are 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day, 7 days in a week and 12 months in a year. You can change between units by multiplying or dividing: 3 minutes = 3 × 60 = 180 seconds.
Worked examples
Evening time to 24-hour
- The clock shows 6:50 in the evening.
- Evening is p.m., so add 12 to the hours.
- 6 + 12 = 18, and the minutes stay the same.
Answer: In 24-hour time it is 18:50.
24-hour to 12-hour
- A digital clock shows 13:26.
- 13 is after 12, so it is an afternoon time.
- Take 12 away from the hours: 13 − 12 = 1.
Answer: 13:26 is 1.26 p.m.
Correcting a conversion
- Ava changes 9 p.m. to 24-hour time.
- You must add 12 to the hours, not 10.
- 9 + 12 = 21.
Answer: 9 p.m. is 21:00, so Ava's 19:00 was wrong.
Changing units of time
- Change 5 hours 30 minutes into minutes.
- 5 hours is 5 × 60 = 300 minutes.
- Add the extra 30 minutes: 300 + 30.
Answer: 5 hours 30 minutes is 330 minutes.
Where you see this in real life
- Reading a station clock that uses the 24-hour clock.
- Setting an alarm for 7.15 a.m. before school.
- Knowing that 20:35 on a ticket means 8.35 in the evening.
Key words
- a.m.
- A time in the morning, from midnight to midday.
- p.m.
- A time in the afternoon or evening, from midday to midnight.
- Analogue clock
- A clock that shows the time with hands.
- Digital clock
- A clock that shows the time in numbers.
- 24-hour clock
- A way of writing time using four digits, from 00:00 to 23:59.