Common time differences
1. Daylight savings time (DST)
Daylight savings time (DST) is used by lots of countries, including Australia, New Zealand, the USA and the UK during their summers. In Daylight Savings time, everyone moves their clocks forward one hour on the first Sunday in October, when the days are getting longer during Spring, and then turning the clocks back to the regular time on the first Sunday in April, when the days are getting shorter.
This means that during DST, our time zones are an extra hour ahead of the standard time zones.
Currently, Queensland, the Northern Territory and Western Australia do not use daylight savings.
2. Time zones
As we learnt last lesson, the world is split up into different time zones, which basically means the time will change depending on where you are in the world.
Australian time zones
Australia is divided into $3$3 time zones (shown in the map on the left). They are:
Eastern Standard Time (AEST): covering Queensland, New South Wales, Australian Capital Territory, Victoria and Tasmania.
Western Standard Time (AWST): covering Western Australia. ( $2$2 hours behind AEST)
Central Standard Time (ACST): covering South Australia, Northern Territory. ( $\frac{1}{2}$12 an hour behind AEST)
The time zones become a bit more tricky during Daylight Savings because not all the states use it. Queensland, the Northern Territory and Western Australia stay on Standard Time. The map on the right shows that during Daylight Savings, Australia actually has $5$5 time zones!
Practice questions
Question 1
Question 2
Complete the table to show the time in each time zone.
WST CST EST $\editable{}$$:$:$\editable{}$ $5$5$:$:$25$25 $\editable{}$$:$:$\editable{}$
$5$5$:$:$11$11 $\editable{}$$:$:$\editable{}$ $\editable{}$$:$:$\editable{}$ $\editable{}$$:$:$\editable{}$ $\editable{}$$:$:$\editable{}$ $12$12$:$:$25$25 $\editable{}$$:$:$\editable{}$ $7$7$:$:$17$17 $\editable{}$$:$:$\editable{}$
Question 3
Luke and Maria board a train at $7$7:$58$58 PM on Saturday from Sydney, New South Wales towards Adelaide, South Australia.
If the trip to Adelaide took $20$20 hours and $22$22 mins then they arrived on $\editable{}$:$\editable{}$ PM Sunday in Adelaide local time.
Luke boards a train from Adelaide, South Australia at $5$5:$45$45 PM on Sunday to Darwin, Northern Territory. If his trip took $28$28 hours and $36$36 mins, then he arrived at $\editable{}$:$\editable{}$ PM Monday Darwin local time.
Maria boards a train from Adelaide, South Australia at $4$4:$55$55 PM Sunday towards Perth, Western Australia. If the trip took her $19$19 hours and $20$20 mins, then she arrived at $\editable{}$:$\editable{}$ AM in Perth local time.
Converting from standard to daylight savings time
- Eastern Standard Time or Standard Time is abbreviated to AEST
- Daylight Savings Time is abbreviated to AEDT
During daylight savings, clocks are moved forward $1$1 hour from the standard time, so $8$8 am standard time would be $9$9 am in daylight savings time, $6$6 pm AEST would become $7$7 AEDT and so on.
Similarly, when we go from daylight savings time to standard time, clocks are moved back $1$1 hour, so $12$12 pm AEDT would be $11$11 am AEST and $14:22$14:22 AEDT would be $13:22$13:22 AEST.
Practice questions
Question 4
If it is $16$16:$14$14 in Sydney in Daylight Savings Time, what time would it be in Eastern Standard Time?
$16$16:$14$14 AEDT would be $\editable{}$:$\editable{}$ AEST.
Question 5
If it is $14$14:$35$35 in Sydney in Eastern Standard Time, what time would it be in Daylight Savings Time?
$14$14:$35$35 AEST would be $\editable{}$:$\editable{}$ AEDT.