Time & Timetables
Calculating durations, reading 12-hour and 24-hour clocks, and interpreting bus and train timetables.
What is Time & Timetables?
Time questions test your ability to read clocks, convert between 12-hour and 24-hour formats, calculate how long something takes, and read timetables.
These questions require careful working because time does not work in base 10 – there are 60 minutes in an hour, not 100. This is where most mistakes happen.
Step-by-Step Method
Convert between 12-hour and 24-hour time
For pm times, add 12 to the hour: 3:30 pm = 15:30. For 24-hour times after 12:00, subtract 12 to get pm.
To find a duration, count on in steps
Count from the start time to the next whole hour, then add the remaining minutes. For example, 09:35 to 11:10: 09:35 to 10:00 = 25 min, 10:00 to 11:10 = 70 min, total = 95 min = 1 hour 35 min.
For timetables, read across the row
Find the correct stop and read across to find departure and arrival times.
Do not subtract time like normal numbers
11:10 minus 9:35 is NOT 2:75. You must borrow from the hours column.
Convert minutes to hours when needed
95 minutes = 1 hour 35 minutes. Divide by 60 to convert.
Worked Examples
Convert 15:45 to 12-hour time.
Working
- 15 is greater than 12, so subtract 12: 15 – 12 = 3.
- It is afternoon, so add pm.
How long is it from 09:35 to 11:10?
Working
- 09:35 to 10:00 = 25 minutes.
- 10:00 to 11:00 = 60 minutes.
- 11:00 to 11:10 = 10 minutes.
- Total: 25 + 60 + 10 = 95 minutes = 1 hour 35 minutes.
A bus leaves Town A at 08:45 and arrives at Town B at 09:22. How long is the journey?
Working
- 08:45 to 09:00 = 15 minutes.
- 09:00 to 09:22 = 22 minutes.
- Total: 15 + 22 = 37 minutes.
Common Mistakes
Subtracting times like normal numbers: 11:10 – 9:35 = 2:75.
Time works in 60s, not 100s. Use the counting-on method or borrow from the hours.
Confusing am and pm when converting.
Midnight = 00:00. Midday = 12:00. Afternoon hours in 24-hour time are 13:00 to 23:59.
Miscounting hours across midday or midnight.
Be extra careful when a duration crosses 12:00 or 00:00. Count in steps.
Top Tips
- The counting-on method is the safest: count to the next whole hour, then add on.
- For quick pm to 24-hour conversion: just add 12. For 24-hour to pm: subtract 12.
- Remember: 12:00 is midday (noon), not midnight. Midnight is 00:00.
- In timetable questions, always check you are reading the right row and column.
Ready to practise?
Put these techniques into action with our free practice papers.
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