End of daylight saving means end of dark mornings

Sunrise times_Sydney_2014_Nick Lomb

Graph indicating sunrise in Sydney throughout the year. It is calculated for 2014 but there is little change from year to year except for the slight shift of the starting and ending dates for daylight saving. Diagram Nick Lomb

If you rise early whether for work, school, gym, a run or walking the dog you are probably sick of the dark mornings that crept up on us very quickly in recent weeks. In that case, help is at hand for this coming Sunday (6 April 2014) is the first Sunday in April and hence daylight saving finishes early that morning.

As can be seen on the above graph the morning before, that is, Saturday morning, is the latest sunrise for the year with the Sun rising at 7:10 am. In the depths of winter at the end of June and the beginning of July the latest sunset is only 7:01 am. So the mornings may well become cooler as the year progresses towards winter, but it is not going to become darker.

If you think that 7:10 am is late for sunrise, spare a thought for the 8000 or so people of the small town of Wentworth in the south-west of NSW. The town is approximately 9° to the west of Sydney and, as each degree of longitude represents four minutes of time, sunrise occurs about 36 minutes later than in Sydney. There the latest sunrise for the year is on Saturday at 7:47 am.

Of course, some people may be disappointed by the earlier sunrise. If you are trying to sleep in for instance you may not appreciate being woken up by light spilling through edges and gaps in blinds and curtains. Also others may have enjoyed the opportunity to see the planet Venus and other objects in the dark morning sky such as passes by the International Space Station.

The above diagram is a useful one as we can see how daylight saving acts to reduce the spread of sunrise times throughout the year. Without daylight saving in early December sunrise would be as early as 4:37 am, which could be a serious difficulty for those trying to sleep at that time.

An interesting, just released, American study suggests that at the start of daylight saving in spring there is a spike of 25% in people experiencing heart attacks, presumably due to losing one hour’s sleep. Conversely, at the end of daylight saving in autumn when the clocks are moved backwards by an hour there is a 21% decrease in heart attacks. The study is based on data from only one American state and the authors suggest that it would be worthwhile comparing the results of their study with data from a state that does not have daylight saving. Maybe a comparison could be done in Australia between hospitals in Sydney and in Perth where there is no daylight saving?

If you like you can stay up till 3 am to change your clocks on Sunday morning. For most people though it is easier and more sensible to do so before going to bed on Saturday evening. And, fortunately, these days many devices like mobile phones, tablets and computers, tend to change automatically without the need for human intervention. However you do it, enjoy the extra hour of sleep on Sunday morning and the lighter mornings from then on.


9 responses to “End of daylight saving means end of dark mornings

  • I think daylight savings is a waste of time.It mucks up my sleep for weeks at each end of its cycle. It shoudve gone to a vote especially when you say that people have become seriously ill as result of it. It wasnt put to a vote because it never would have got started. So much for democracy in Australia. We are little people,silly people,greedy,barbarous and cruel.

    • Peter, you are still free to wake and sleep by the position of the Sun, not the clock, if you wish! I think you are being a little harsh on everyone – people I meet are generous, friendly and humane.

  • I would just like to say on the issue of daylight saving in this country and that is how do you get an extra hour of daylight that just doesn’t exist in the real world. After all if you really got an extra hour in reality you wouldn’t need to move any clocks forward at all. And considering our biggest time clock in the world which is our biggest star ( the sun ), it doesn’t decide to stay up an extra hour just to fulfil stupid human ideas and because it’s summer.

    • Steve, Of course the extra hour of daylight doesn’t exist, it’s just ‘borrowed’ from the morning! Daylight saving began as an electricity saving measure during WWII, but the extra hour of daylight between finishing work and sunset appeals to many people, particularly those in the urban areas. The majority of people, in at least some states in Australia, still think its a good idea.

  • I think the rule that would be good for daylight saving would be if the extra hour added on did not result in a sunrise being later than it is in the middle of winter – so therefore it should finish at least 2 weeks earlier.

    Same should apply for the start – Daylight saving used to start so late that sunrise was 5am in Sydney at the end of October. Now, the start is earlier which is goods, but it could start 1-2 weeks earlier so that the earliest sunrise without daylight saving is not earlier than the earliest sunrise with daylight saving.

    • Hello Andy. I am pleased that you like the graph as I think that it is most informative. For simplicity I did not do a graph of sunset times for the year this time, but I have done so on a previous blog post four years ago.

  • The fact that the latest sunrise for the year occurs in April rather than mid-winter just confirms for me that daylight saving lasts far too long. It used to end on the first Sunday in March, which makes far more sense.

    And regarding Broken Hill – doesn’t it use Australian central (Adelaide) time? So it’s latest sunrise would be closer to 7.18am.

    • Hello Roberto. Oops! I had forgotten that Broken Hill keeps South Australian time. Thank you for pointing it out. I have now corrected the post to discuss the town of Wentworth instead. With regard to the dates of the start and ending of daylight saving I will just point out that the current arrangement is based on an agreement between NSW, Victoria, Tasmania, ACT and South Australia. Whatever minor difficulties there maybe with this arrangement going back to separate schemes in different states would be far worse.

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