Daylight savings means that you add an hour to the normal time.
If the sun usually sets at 6pm then if you add an hour then it will set at 7pm (later on in the day).
For example, WA never uses daylight saving, but NSW does. The normal time difference in 2 hours. If it's 8am in Perth then it's 10am in Sydney. When daylight savings comes in, we add an hour to the Sydney time, so when it's 8 am in Perth it's 11 am in Sydney, so the time difference becomes 3 hours.
Does that help?
Another bit of trivia ... the time difference between Sydney and London is 10 hours, but it never actually is ... at the moment it's 9 hours because UK is on Summer time (so add an hour to their time, so their 1 less hour behind us) ... then when we go onto daylight savings, they go off it, so add an hour to our time, take an hour off theirs, so suddenly 11 hours time difference.
Good luck on Tuesday
