Cambridge Primary (1-6). Stage 5. Science. Learner's Book - Unit 6: Seasons and adaptations of plants and animals - Question 36

Look at the times of sunrise and sunset for Cape Town during a week in February and a week in March. The length of day is calculated by subtracting the sunrise time from the sunset time.

Sunrise and sunset times for Cape Town, South Africa

| Date | Sunrise | Sunset | Length of day |
|:-|:-:|:-:|:-:|
| 1 February | 06:08 | 19:51 | 13h 43m |
| 2 February | 06:09 | 19:51 | 13h 42m |
| 3 February | 06:10 | 19:50 | 13h 40m |
| 4 February | 06:11 | 19:49 | 13h 38m |
| 5 February | 06:12 | 19:48 | 13h 36m |
| 6 February | 06:13 | 19:47 | 13h 34m |
| 7 February | 06:14 | 19:46 | 13h 32m |
| 14 March | 06:45 | 19:06 | 12h 21m |
| 15 March | 06:46 | 19:04 | 12h 18m |
| 16 March | 06:46 | 19:03 | 12h 17m |
| 17 March | 06:47 | 19:01 | 12h 14m |
| 18 March | 06:48 | 19:00 | 12h 12m |
| 19 March | 06:49 | 18:59 | 12h 10m |
| 20 March | 06:50 | 18:57 | 12h 07m |

Explain why, using knowledge from the last topic, the length of day changes.