Time and Timetables
What the exam tests
Time and timetables tests reading clocks, converting between 12-hour and 24-hour time, calculating time intervals, and reading bus, school or train timetables.
Core rules
- 60 seconds = 1 minute; 60 minutes = 1 hour; 24 hours = 1 day.
- For pm times in 24-hour form, add 12 to the hour, except 12 pm, which is 12:00. Midnight is 00:00; noon is 12:00.
- To find a duration, count forward from the start time to the end time, or subtract with borrowing in 60s.
- In a timetable, read across a row for one journey and down a column for one time. Check whether times are am or pm.
- If an arrival time is earlier than the departure time, the journey crosses midnight; add 24 hours before subtracting.
Worked example
A bus leaves at 08:45 and arrives at 11:20. How long is the journey? From 08:45 to 11:00 is 2 hours 15 minutes. From 11:00 to 11:20 is another 20 minutes. Total = 2 hours 35 minutes. Alternatively, 11:20 − 08:45 = 2:35 after borrowing 60 minutes.
Traps that cost marks
Do not treat 1 hour as 100 minutes. Do not write 14:00 as 4:00 pm without checking the am/pm label. When borrowing in a time subtraction, borrow 60, not 10. Do not assume every timetable uses the same day; an overnight arrival needs care. Read the column headings so you do not use the arrival time as the departure time.