Work out the time anywhere with a time-zone map

Grade 9 Social Studies Worksheet

Circle the best answer.

1. Read this first

   Use this

   Card A. Offsets in July, and when clocks change. Charleston: UTC−4 in summer (Eastern Daylight Time, from the second Sunday in March to the first Sunday in November), UTC−5 in winter. London: UTC+1 in summer (British Summer Time, from the last Sunday in March to the last Sunday in October), UTC+0 in winter. Phoenix: UTC−7 all year (Arizona, apart from the Navajo Nation, has not changed clocks since 1968); the Navajo Nation, in northeast Arizona, does change its clocks. Tokyo UTC+9 and Beijing UTC+8: no daylight saving time. Moscow UTC+3 all year since 2014. Sydney: UTC+10 in winter, UTC+11 in summer, from the first Sunday in October to the first Sunday in April. Card B. The 2027 calendar for those Sundays. Second Sunday in March: 14 March. Last Sunday in March: 28 March. First Sunday in April: 4 April. First Sunday in October: 3 October. Last Sunday in October: 31 October. First Sunday in November: 7 November. Clocks change on the Sunday itself.

2. 1.

   By how many hours is London ahead of Charleston on 20 March 2027, Ari asks?

   • 6 hours: London has changed and Charleston has not, so London is further ahead
   • 4 hours: Charleston has changed its clocks and London has not yet
   • 5 hours, the gap in January and in July, as for most of the year
   • 1 hour, the size of the single clock change made by this date

3. Use this

   Card A. Offsets in July, and when clocks change. Charleston: UTC−4 in summer (Eastern Daylight Time, from the second Sunday in March to the first Sunday in November), UTC−5 in winter. London: UTC+1 in summer (British Summer Time, from the last Sunday in March to the last Sunday in October), UTC+0 in winter. Phoenix: UTC−7 all year (Arizona, apart from the Navajo Nation, has not changed clocks since 1968); the Navajo Nation, in northeast Arizona, does change its clocks. Tokyo UTC+9 and Beijing UTC+8: no daylight saving time. Moscow UTC+3 all year since 2014. Sydney: UTC+10 in winter, UTC+11 in summer, from the first Sunday in October to the first Sunday in April. Card B. The 2027 calendar for those Sundays. Second Sunday in March: 14 March. Last Sunday in March: 28 March. First Sunday in April: 4 April. First Sunday in October: 3 October. Last Sunday in October: 31 October. First Sunday in November: 7 November. Clocks change on the Sunday itself. Card C. Harlow Books (made up) has offices in Charleston and London. Staff in both work from 9:00 to 17:00 on their own local clocks.

4. 2.

   How many hours a day do the two offices’ working hours overlap on 20 March 2027, Bo asks?

   • 3 hours, the overlap for most of the year when the gap is 5 hours
   • 8 hours, since both offices work the same 9:00 to 17:00 day
   • 5 hours, the usual gap between the two offices’ clocks
   • 4 hours: London 13:00 to 17:00 is Charleston 9:00 to 13:00

5. Use this

   Card A. Offsets in July, and when clocks change. Charleston: UTC−4 in summer (Eastern Daylight Time, from the second Sunday in March to the first Sunday in November), UTC−5 in winter. London: UTC+1 in summer (British Summer Time, from the last Sunday in March to the last Sunday in October), UTC+0 in winter. Phoenix: UTC−7 all year (Arizona, apart from the Navajo Nation, has not changed clocks since 1968); the Navajo Nation, in northeast Arizona, does change its clocks. Tokyo UTC+9 and Beijing UTC+8: no daylight saving time. Moscow UTC+3 all year since 2014. Sydney: UTC+10 in winter, UTC+11 in summer, from the first Sunday in October to the first Sunday in April. Card B. The 2027 calendar for those Sundays. Second Sunday in March: 14 March. Last Sunday in March: 28 March. First Sunday in April: 4 April. First Sunday in October: 3 October. Last Sunday in October: 31 October. First Sunday in November: 7 November. Clocks change on the Sunday itself.

6. 3.

   By how many hours is Sydney ahead of London on 30 March 2027, Kira asks?

   • 10 hours: London is on UTC+1 and Sydney is still on UTC+11
   • 9 hours, the gap after Sydney changes on 4 April
   • 11 hours, the gap before London changes on 28 March
   • 12 hours, adding the two clock changes to the gap

7. Use this

   Card D. Dara (made up for practice) uses one offset, UTC+3, for the whole country. The east city Kell and the west city Orm lie at the same latitude, 45° of longitude apart. Earth turns 15° an hour, so 1° of longitude is 4 minutes of sun time. In midsummer the sun rises in Kell at 04:30 on the clock. A government report says one zone makes trade easier because the offices in both cities keep the same clock time.

8. 4.

   Dara’s report says one zone helps trade. What does the zone give and what does it cost, Luz asks?

   • Trade gets one clock and the sun matches in both cities, so it costs nothing
   • Trade gets one clock, and the sun rises in Orm at 04:30 as in Kell
   • Trade gets one clock; the cost is sun time that differs by about three hours
   • Trade loses from a three-hour clock gap, while sun time matches

9. Use this

   Card B. The 2027 calendar for those Sundays. Second Sunday in March: 14 March. Last Sunday in March: 28 March. First Sunday in April: 4 April. First Sunday in October: 3 October. Last Sunday in October: 31 October. First Sunday in November: 7 November. Clocks change on the Sunday itself. Card E. A made-up firm has offices in Phoenix, Charleston and London. Staff work 9:00 to 17:00 local time. Phoenix is UTC−7 all year. Charleston is UTC−5 in winter and UTC−4 from 14 March 2027. London is UTC+0 in winter and UTC+1 from 28 March 2027.

10. 5.

    On 20 March 2027, how many hours a day are all three offices at work at once, Milo asks?

    • 4 hours, the overlap that London and Charleston have on their own
    • No hour, since three offices on three offsets cannot share a working hour
    • 3 hours, the clock gap between Phoenix and Charleston on that date
    • 1 hour: 16:00 in London, 12:00 in Charleston, 9:00 in Phoenix
11. 6.

    Noah’s note says: “On 30 March 2027 the three offices still share an hour, as on 20 March.” Which fix is right?

    • Leave it: Phoenix did not change, so the shared hour stays the same
    • Change it: Charleston changed on 14 March, so the shared hour is gone
    • Change it: Phoenix moved its clocks forward, so the shared hour is gone
    • Change it: London moved on 28 March, so its day ends when Phoenix’s starts

12. Use this

    Card A. Offsets in July, and when clocks change. Charleston: UTC−4 in summer (Eastern Daylight Time, from the second Sunday in March to the first Sunday in November), UTC−5 in winter. London: UTC+1 in summer (British Summer Time, from the last Sunday in March to the last Sunday in October), UTC+0 in winter. Phoenix: UTC−7 all year (Arizona, apart from the Navajo Nation, has not changed clocks since 1968); the Navajo Nation, in northeast Arizona, does change its clocks. Tokyo UTC+9 and Beijing UTC+8: no daylight saving time. Moscow UTC+3 all year since 2014. Sydney: UTC+10 in winter, UTC+11 in summer, from the first Sunday in October to the first Sunday in April.

13. 7.

    A call is set for 9:00 in Phoenix in July. Which cities have it between 8:00 and 18:00 on their clocks, Pia asks?

    • Charleston, London and Beijing (00:00)
    • Charleston (12:00) and London (17:00)
    • Tokyo (01:00) and Beijing (00:00), the next cities east
    • Charleston alone (12:00), since London is too far east

14. Use this

    Card A. Offsets in July, and when clocks change. Charleston: UTC−4 in summer (Eastern Daylight Time, from the second Sunday in March to the first Sunday in November), UTC−5 in winter. London: UTC+1 in summer (British Summer Time, from the last Sunday in March to the last Sunday in October), UTC+0 in winter. Phoenix: UTC−7 all year (Arizona, apart from the Navajo Nation, has not changed clocks since 1968); the Navajo Nation, in northeast Arizona, does change its clocks. Tokyo UTC+9 and Beijing UTC+8: no daylight saving time. Moscow UTC+3 all year since 2014. Sydney: UTC+10 in winter, UTC+11 in summer, from the first Sunday in October to the first Sunday in April. Card B. The 2027 calendar for those Sundays. Second Sunday in March: 14 March. Last Sunday in March: 28 March. First Sunday in April: 4 April. First Sunday in October: 3 October. Last Sunday in October: 31 October. First Sunday in November: 7 November. Clocks change on the Sunday itself.

15. 8.

    On 20 March 2027, what is the clock gap between Phoenix and a Navajo Nation office, Ren asks?

    • 3 hours, as between Phoenix and Charleston in July, after the March change
    • 1 hour: the Navajo Nation changed its clocks and Phoenix did not
    • 2 hours, as between Phoenix and Charleston in January
    • 0 hours, since both offices are in Arizona and share a state

16. Use this

    Card F. The International Date Line runs roughly along 180°, but it bends. In 1995 Kiribati, whose islands lie on both sides of 180°, had the line moved east so that all its islands share one date.

17. 9.

    Tala’s note says: “The date line bends because Earth’s surface is curved.” Which fix is right?

    • Change it: it bends so places that work together share a date
    • Change it: it bends to follow the lines of latitude across the ocean
    • Change it: it bends so each time zone is exactly 15° wide on the map
    • Leave it: a flat map must bend any line that is drawn on a sphere, so the bend has no other reason

18. Use this

    Card D. Dara (made up for practice) uses one offset, UTC+3, for the whole country. The east city Kell and the west city Orm lie at the same latitude, 45° of longitude apart. Earth turns 15° an hour, so 1° of longitude is 4 minutes of sun time. In midsummer the sun rises in Kell at 04:30 on the clock. A government report says one zone makes trade easier because the offices in both cities keep the same clock time. Card G. A survey of Dara (made up). Share of workers whose winter workday starts before sunrise: 70 percent in the west, 20 percent in the east. Firms in both cities say one clock makes orders easier to handle.

19. 10.

    Zee’s note says: “One zone helps everyone in Dara equally.” Which fix is right?

    • Leave it: 70 and 20 percent average 45 percent, a fair share for each side
    • Change it: more eastern workers start in the dark, 70 percent against 20 in the west
    • Change it: firms gain a clock, but dark starts are 70 percent west, 20 east
    • Leave it: firms in both cities say one clock makes orders easier to handle