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
   • 5 hours, the gap in January and in July, as for most of the year
   • 4 hours: Charleston has changed its clocks and London has not yet
   • 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?

   • 5 hours, the usual gap between the two offices’ clocks
   • 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
   • 4 hours: London 13:00 to 17:00 is Charleston 9:00 to 13:00
5. 3.

   In 2027, on how many calendar days is the London–Charleston gap 4 hours, counting both short periods, Esme asks?

   • 7 days, the autumn week when the two places have changed on different Sundays
   • 21 days: 14 to 27 March, and 31 October to 6 November
   • 14 days, since the gap is 4 hours in the spring weeks and at no other time
   • 28 days: two weeks in March and two in autumn, since each change is two weeks apart

6. 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.

7. 4.

   Who bears the cost of Dara’s single zone, Jun asks?

   • Western residents: Orm’s sun comes about three hours later on the clock
   • No one, since one zone puts the clocks on one sun time as well
   • Eastern residents, since Kell’s sun comes later on the clock than Orm’s
   • Traders, since one zone adds a three-hour clock gap between the two cities

8. 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.

9. 5.

   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

10. 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.

11. 6.

    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 loses from a three-hour clock gap, while sun time matches
    • Trade gets one clock; the cost is sun time that differs by about three hours

12. 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.

13. 7.

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

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

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.

15. 8.

    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?

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

16. 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.

17. 9.

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

    • 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
    • 3 hours, as between Phoenix and Charleston in July, after the March change

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?

    • 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
    • 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