# Length of day at equinox

**URL:** <https://boards.straightdope.com/t/length-of-day-at-equinox/488262>\
**Category:** Factual Questions\
**Created:** [March 4, 2009, 12:46pm UTC](https://boards.straightdope.com/t/length-of-day-at-equinox/488262 "2009-03-04T12:46:24Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\
**Post date:** [March 4, 2009, 12:46pm UTC](https://boards.straightdope.com/t/length-of-day-at-equinox/488262/1 "2009-03-04T12:46:24Z")

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According to this site:

> **[Current Local Time in Quito, Ecuador](https://www.timeanddate.com/worldclock/ecuador/quito)**
>
> Current local time in Ecuador – Quito. Get Quito's weather and area codes, time zone and DST. Explore Quito's sunrise and sunset, moonrise and moonset.

the length of the day in Quito, which is virtually on the equator (14’ S) is 12 hours and 6 minutes:  
Sunrise at 6:22 AM in direction 96° East by south Map direction East by south  
Sunset at 6:29 PM in direction 264° West by south Map direction West by south  
Duration of day: 12 hours, 6 minutes (1 second shorter than yesterday)  
Sun near zenith at 12:26 PM at altitude 84° above horizon

We are close enough to the equinox that these numbers are not going to change before that. Of the extra 6 minutes, 2 can be accounted for by the 1/2 degree diameter of the sun. Where do the other 4 minutes come from? Is there really 2 degrees of refraction at each end?

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**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\
**Post date:** [March 4, 2009, 1:51pm UTC](https://boards.straightdope.com/t/length-of-day-at-equinox/488262/2 "2009-03-04T13:51:47Z")

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First of all, it’s not the equinox.

According to [Wikipedia](http://en.wikipedia.org/wiki/Day_length):

> [@Wiki](#):
>
> On the Equator, the length of day is not exactly 12 hours all the year round, but rather — due to atmospheric refraction and the size of the Sun — exceeds 12 hours by about 7 minutes each day

That seems to agree your link.

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**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\
**Post date:** [March 4, 2009, 3:24pm UTC](https://boards.straightdope.com/t/length-of-day-at-equinox/488262/3 "2009-03-04T15:24:37Z")

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Thanks. It is close enough to the equinox that at Quito the day length is changing by 1 second each day. In Monteal, by contrast, it changed by 3’10" from yesterday.