Sundials

[John Pickering]

Evening all,

i built an equatorial sundial. Now I want to add a plaque with information about how to correct the time shown by the shadow to clock time (equation of time, latitude, daylight saving etc).  This needs to be for  Christchurch.  Does anyone know a good place to get the corrections from?

 

[Preetha Sreedharan]

Hello, cool sundial time lord!!

Rob thinks that the plaque for the Botanical Gardens sundial is still there with the graph even though the sundial is no longer there… hope that helps.

[Terry Richardson]

Talk to Geoff Shaw (ICU)

He makes corrected calibrated sundials and will know the math.

Good luck. A worthy project

Cheers

Terry

[Orlon Petterson]

Hi John

The following PDF for the Southern Hemisphere Equation of Time is what you want to look at.

https://www.sws.bom.gov.au/Category/Educational/The%20Sun%20and%20Solar%20Activity/General%20Info/EquationOfTime.pdf

[John Pickering]

Thank you everyone.  I am going with a simple table like in the sundial in the botanical gardens (except I add the extra 30 mins for longitude). Will post pics when all finished.  In the meantime, there is a temporary notice and lots of people stopping to look and check their watched 🙂

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