<p>Received an answer on the astronomy stack. <a href="https://astronomy.stackexchange.com/questions/22239/getting-solar-noon-from-sunset-and-sunrise/22241#22241">https://astronomy.stackexchange.com/questions/22239/getting-solar-noon-from-sunset-and-sunrise/22241#22241</a></p>

<p>The short of it is that yes, this is reasonably accurate for most geographies, but can vary significantly in polar regions. For most cases, middling the difference of sunrise and sunset is sufficient. </p>

CC BY-SA 3.0
2017-08-21T23:38:24.587Z
2017-08-21T23:38:24.587Z
Brad
<p>I've seen the solar noon formula described as <code>snoon = 720 – 4*longitude – eqtime</code>. I'm curious if it is equally reliable within a relatively small margin of error (+-60 seconds) to simply get the midpoint between sunrise and sunset, given that data is already calculated and available. </p>

<p>Is there any occasion when solar noon wouldn't be equal time from sunrise and sunset, give or take the aforementioned margin of error? </p>

CC BY-SA 3.0
2017-08-22T07:28:01.993Z
I'm voting to close this question as off-topic because it is crossposted to Astronomy.SE, where it is a better fit *and* got an answer (https://astronomy.stackexchange.com/questions/22239/getting-solar-noon-from-sunset-and-sunrise/22241#22241)
Jan Doggen
CC BY-SA 3.0
2017-08-22T15:55:03.280Z
Good question (and those not familiar with what eqtime is, [this](https://physics.stackexchange.com/questions/38270/why-is-the-solar-noon-time-different-every-day) Astronomy StackExchange question discusses it some).  I would think that'd be just fine, but can't prove it.  I believe I had a textbook that discusses it further, but not near right now.
JeopardyTempest
CC BY-SA 3.0
2017-08-22T15:56:45.330Z
That's what I get for leaving it open since yesterday and just now adding the comment.  Boo crossposting! :-D
JeopardyTempest
<earth-rotation><sun><solar-terrestrial-physics><time>
Calculating Solar Noon from Sunrise and Sunset
Brad
# Calculating Solar Noon from Sunrise and Sunset

(Asked by: username_0 on 2017-08-21)

I've seen the solar noon formula described as `snoon = 720 – 4*longitude – eqtime`. I'm curious if it is equally reliable within a relatively small margin of error (+-60 seconds) to simply get the midpoint between sunrise and sunset, given that data is already calculated and available.

Is there any occasion when solar noon wouldn't be equal time from sunrise and sunset, give or take the aforementioned margin of error?

**Tags:** earth-rotation, sun, solar-terrestrial-physics, time

> **Comments:**
> **username_1**: I'm voting to close this question as off-topic because it is crossposted to Astronomy.SE, where it is a better fit *and* got an answer (https://astronomy.stackexchange.com/questions/22239/getting-solar-noon-from-sunset-and-sunrise/22241#22241)  
> **username_2**: Good question (and those not familiar with what eqtime is, [this](https://physics.stackexchange.com/questions/38270/why-is-the-solar-noon-time-different-every-day) Astronomy StackExchange question discusses it some).  I would think that'd be just fine, but can't prove it.  I believe I had a textbook that discusses it further, but not near right now.  
> **username_2**: That's what I get for leaving it open since yesterday and just now adding the comment.  Boo crossposting! :-D  

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## 1 answers

### Answer by username_0 on 2017-08-21. Score: 0

Received an answer on the astronomy stack. <https://astronomy.stackexchange.com/questions/22239/getting-solar-noon-from-sunset-and-sunrise/22241#22241>

The short of it is that yes, this is reasonably accurate for most geographies, but can vary significantly in polar regions. For most cases, middling the difference of sunrise and sunset is sufficient.


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