Time and Timetables

Time questions are a favourite on the CSSE 11+ maths paper. These questions test whether you can work confidently with hours, minutes, the 24-hour clock, and real-world timetables. The CSSE is known for multi-step time problems that combine calculation with careful reading. This lesson will make sure you are fully prepared.

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Telling the Time

The 12-Hour and 24-Hour Clock

12-hour clock	24-hour clock
12:00 midnight	00:00
6:30 am	06:30
12:00 noon	12:00
1:00 pm	13:00
4:45 pm	16:45
9:15 pm	21:15
11:59 pm	23:59

To convert from 12-hour to 24-hour (afternoon/evening): add 12 to the hours.

• 3:20 pm = 15:20

To convert from 24-hour to 12-hour: if the hour is 13 or more, subtract 12 and add "pm".

• 18:45 = 6:45 pm

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Calculating Time Intervals

The most common time question: "How long is the journey from ... to ...?"

The Counting-On Method

This is the safest method. Count from the start time to the end time in stages.