What if it was always Daylight Saving Time?

By Aaron Schiff 14/04/2015


The end of New Zealand Daylight Saving Time is upon us,* and every year this makes me cranky. The evening darkness seems to make Auckland’s damp winters feel extra long.

Out of curiosity I thought I’d look at what the sunrise and sunset times would be if we used NZDST for the whole year. The Royal Astronomical Society of New Zealand publishes tables of sunrise and sunset times for various places in New Zealand. Here’s what the times would look like if we used NZDST year-round (apologies for the ugly Excel charts, I didn’t have much time):

sunrise

sunset

The dashed lines in the charts indicate where NZDST begins and ends; during Standard Time I’ve added an hour to simulate year-round NZDST. So if we always used NZDST, in mid-winter people in Auckland would see the sunrise a little after 8.30 am, whereas in Christchurch the sun wouldn’t come up until a little after 9 am, and in Dunedin sunrise would be at about 9.20 am. Hmm, maybe a little late.

At the other end of the day, interestingly there isn’t much difference in sunset times between Wellington, Christchurch, and Dunedin in mid-winter (I’m sure there’s some science-y reason for this). If we were on NZDST, those cities would have sunset at around 6.00 pm in mid-winter, whereas in Auckland it would be about 15 minutes later.

Another thing to note is that the further north you are, the curves are a little bit flatter. So while the mid-winter dip or summer peak aren’t as extreme, you also spend more time around the minimum / maximum points in Auckland compared to Dunedin. This might be what makes it feel like mid-winter drags along forever in Auckland (or maybe it’s just my imagination).

Also, if you haven’t already seen it, go check out Dumpark’s fascinating and beautiful visualisation of sunlight in Wellington.

*Editor’s note: Originally published at Aaron’s blog 2 April.