The case for two time zones in Queensland – a solution to
the daylight savings dilemma?
The problem in the ongoing debate about daylight saving in Queensland is that the
rapidly growing urbanized coastal strip in southeastern Queensland lies so far to the
east in relation to the rest of the state. Its southern location exacerbates the problem
during summer.
In winter the sun rises in a line parallel to the Queensland coast with the result that the
coastal cities have sunrise at much the same time. In summer the sun rises in a line
parallel to the NSW coast with the result that the southeastern corner of Queensland has
sunrise even earlier in relation to the rest of the state than would be expected from its
eastern location.
Mean solar time is the average time of the day when the sun is at its highest point.
Queensland is an enormous state and therefore has a wide variation in the mean solar
times for its different regions. The mean solar time for Brisbane is 11:45am. By contrast
the mean solar time for Cairns is about 40 minutes later at 12:25pm and Mt Isa a full
hour later at 12:45pm.
Local authorities when choosing a time zone for a region try to ensure that the mean
solar time will fall between 12:00pm and 1:00pm. This is the time band that will allow
maximum utilization of the daylight hours for the majority of people in that region. All the
major centres in Australia, with the exception of Brisbane, fall into this time band e.g.
Adelaide 12:20pm, Darwin 12:45pm, Melbourne 12:25pm, Perth 12:20pm and Sydney
12:05pm.
Time zones allow local time to approximate the mean solar time. There has been a
general trend to push the boundaries of time zones further west in order to create a
permanent daylight saving time effect. Urban regions are more likely to embrace this
than rural areas. As will be the case next year in Australia, there is also a worldwide
trend to extend the period of daylight saving. The local authorities are aware of the
benefits to lifestyle, energy savings, road safety and crime prevention that occur from
this shift west.
The higher latitudes of the southern regions of Australia result in relatively longer
daylight hours during summer and this allows some leeway in shifting the mean solar
time to a band between 1:00pm and 2:00pm. During daylight saving the mean solar time
for Adelaide, Perth and Melbourne will be an hour later at about 1:20pm. Darwin at its
lower latitude does not have this leeway and its mean solar time remains at 12:45pm
year round.
At latitudes of less than 28º (approximately the SEQ region) daylight hours vary less
between summer and winter and there is very little leeway to shift the mean solar time
outside of the 12:00pm to 1:00pm time band. This is well illustrated by comparing Cairns
and Melbourne. Both are positioned along similar lines of longitude (145º E) and
therefore have similar mean solar times (12:25pm). In Melbourne the sun rises at
7:30am in July and 5:15am in January without daylight saving. Daylight saving shifts
sunrise in January to 6:15am which is still over 75 minutes earlier than in winter. Cairns
however has sunrise at 6:00am in January and 6:45am in July. If daylight saving were
introduced in Cairns, sunrise would move to around 7:00am in January or at least 15
minutes later than in mid-winter!
In Brisbane shifting the clocks in summer would result in sunrise during January still
being about 40 minutes earlier than in July. This time difference decreases rapidly north
of Brisbane and becomes negative north of Bundaberg. This demonstrates how
inappropriate and unworkable statewide daylight saving would be.
Most people would therefore agree that regions north of about 28º S do not need
daylight saving provided that their mean solar times fall between 12:00pm and 1:00pm.
SEQ is the only urbanized region in Australia (irrespective of latitude) where mean solar
time does not fall between 12:00 pm and 1:00pm. As noted above, its location in the
southern part of Queensland exacerbates the problem in summer. Thus the call from the
southeastern corner is not so much about introducing daylight saving but rather about
shifting the mean solar time for the region from 11:45am to 12:45pm. The rest of
Queensland is already in the correct time zone and therefore opposes daylight saving as
this would shift the mean solar time in that region to the band between 1:00pm and
2:00pm.
There is an argument that SEQ should be an hour ahead of the rest of Queensland year
round based on a mean solar time of 12:45pm (the same as Darwin). The benefit would
be that the last warm hour of winter sunshine could be utilized by more people as it
would occur an hour later between 5pm to 6pm. The drawback would be that the sun
would rise an hour later but even in mid-winter it would still be starting to get light by
7:10am at the latest. SEQ would then essentially then have the same times of daylight
throughout the year that Mount Isa has at present.
Daylight saving and time zones are two very different issues.
Daylight saving is best utilized, but not essential, in the southern states which have
latitudes of over 28º and longer summer days. Two time zones are required in states
with large east-west dimensions irrespective of latitude whose range of solar time
exceeds one hour or if the solar time range for the region is skewed to one side or the
other of the 12:00pm to 1:00pm band.
Queensland fulfils both criteria for a state that needs two time zones. In its current time
zone the mean solar time range is from 11:45am to12:55pm. The mean solar time is
therefore skewed to the left (11:45am to 12:00pm) and has a range of greater than one
hour.
Ten of the larger states in the USA ranging from Florida to Oregon have two time zones.
All of them with the exception of Texas have a land area less than a quarter the size of
Queensland. The western part of the Florida panhandle (a region of 200km by 60km
representing less than 10% of the land area of Florida) is in a different time zone to the
rest of the state. Although the state capital is only 75km to the east of this region, the
residents of that region have decided that the advantages of being in the correct time
zone outweigh the disadvantages of being in a different time zone to the capital and the
rest of the state. Tennessee and Kentucky, unable to fit into one of the existing time
zones without skewing their mean solar time band to one side or the other, have elected
to have two time zones. The states are divided almost exactly in half by the time zone
line. The states could have fitted into a single time zone with a half hour time difference
to the states around them, but it would appear that two time zones is the preferred
option.
Five of the ten provinces of Canada utilize two time zones. The province of British
Columbia in Canada is of similar geographic size and shape as Queensland. The
southeastern corner of British Columbia (an area no bigger than the
Brisbane/Ipswich/Gold Coast and Sunshine Coast region) is one hour ahead of the rest
of the province. I lived in the middle of British Columbia for five years and was unaware
of any opposition to or controversy regarding the two time zones. There is no “deep
chasm” - Premier Beatties words last week - dividing the people of British Columbia. The
two time zones enable the people of British Columbia to live in their geographically
correct time zone and utilize the daylight hours. British Columbia, as reflects its high
latitude, also has daylight saving.
Not all states in the USA have daylight saving. Arizona, although it is one of the larger
states, only has a mean solar time range of 12:20pm to 12:40pm. It is therefore perfectly
positioned in the middle of the 12:00pm to 1:00pm band. Therefore despite its northern
latitude of 33 º - 37 º N (the northern equivalent of the latitude between Sydney and
Melbourne) it has elected not to have daylight saving as its mean solar time allows
maximum utilization of the daylight hours year round.
Arizona’s largest city Phoenix is the seventh largest city in the USA. It is a major airline
hub and industrial base for the southwestern region of the USA. Almost all the other
states in the USA observe daylight saving. This means that twice a year business in
Phoenix and the rest of the state have to adjust to new time differences with the rest of
the country. While it would probably be more convenient for business if these
adjustments did not have to be made, it is the preference of the people that they live in a
time zone that is most suited to them.
There is a common misconception that the business community is the prime mover for
SEQ to adopt daylight saving. It is in fact the people of southeastern Queensland, most
of whom do not care what the time is in Sydney or Melbourne. The business community
in SEQ wants daylight saving while the business community in the rest of Queensland is
against it. This reflects the view of the people in each of their regions and it is not
surprising that each business community supports that regional view.
The argument that two time zones would shift a Queensland/NSW problem to an
intrastate problem has some merit but is insignificant when compared to the lifestyle,
energy and road safety benefits that the people in SEQ would immediately have. One
time zone for Queensland business may be convenient but it is not essential. In other
parts of the world any inconvenience of having two time zones in one state is easily
adapted to and accommodated.
It is not surprising that the new demographics, increasing urbanization and changing
lifestyle demands in southeastern Queensland are creating the perfect storm that is
increasing the momentum for changing the clocks in that region.
On the other hand, the fierce opposition to changing the clocks in the rest of the state
will continue. The regions latitude and position in the correct time zone will ensure that
this position will never change. The residents of the region have been unfairly maligned
over their entirely appropriate and correct views on daylight saving in their region.
In summary, Queensland needs two time zones for at least the summer months based
purely on its latitude and broad range of solar time.
Until the need for two time zones is recognized the issue of daylight saving in
Queensland will never be resolved.