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As the question indicates, I would like to know the sunrise and sunset times of a location. This is to evaluate the impact of day and night variations of a time series. Is there a way to download this data? Is there some other way to divide the aforementioned time series into day and night for this purpose. I am new to this and any help would be greatly appreciated. It would be fine even if this is a paid service. Thanks.

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    $\begingroup$ That's not recorded. but you can calculate it with a tool of your choice, e.g. stellarium or on websites like heavens-above.com/… $\endgroup$ Jun 5, 2023 at 13:36
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    $\begingroup$ JPL Horizons might be the easiest and most accurate: ssd.jpl.nasa.gov/horizons/app.html# $\endgroup$ Jun 5, 2023 at 18:47
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    $\begingroup$ The US Naval Observatory has a site for this: aa.usno.navy.mil/data/RS_OneYear . Some caveats: (1) you can only download one year of data at a time (2) the format is human-readable but it would take a bit of work to get it nice for a machine (3) they've chosen not to implement daylight savings time. $\endgroup$ Jun 5, 2023 at 23:21
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    $\begingroup$ This page may be of some use, it generates a graph of the rise and set times of the Sun (and other objects) over any specified time period. celestialprogramming.com/riseandsetgraph/index.html $\endgroup$ Jun 6, 2023 at 18:49
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    $\begingroup$ Similar to the US Naval Observatory site mentioned in another comment Geoscience Australia does the same, but the output can be downloaded as a csv file. Caveat: output is for either one day or one year, you nominate the year. $\endgroup$
    – Fred
    Jun 7, 2023 at 4:06

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You might want to find an astronomical almanach or year book. They usually have tables of sunrise and sunset times. They usually cover only one year, though and accurate times only for selected places.

You might also consult a tool of your choice like stellarium or use websites like Heavens Above to check the sunset and sunrise times for specific locations. This allows you often arbitrary choice of a location and a large range in time.

Or you can use a short python script to generate you the output for a timeframe and location of your choice. Some possible scripts are given in this answer.

See also the various questions and answers in this SE on sunrise or sunset times.

Either case, make sure you use a reference with a location near you or get your geographic coordinates as accurate as you can... 100km already make several minutes of difference. If you need an accuracy of only to about one or two minutes: then you can get the data from one year and re-use it for any other.

Generally: the rise and set times of the sun do repeat roughly yearly, but not exactly: we do have leap years which account for the fact one revolution of Earth around the Sun does not fit an exact integer number of days in a year. But one can calculate this to reasonably great precision as the equation of motions and the current positions and speed and masses of all important objects in the Solar System are reasonably-well known. And thus one can predict the future or get knowledge about it in the past up to a certain extend (this extend can well be many millenia, depending on required accuracy and property.

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  • $\begingroup$ Thank you for the answer. I am a total bonehead when it comes to astronomy. So, pardon this question: Is the sunrise and sunset times in a particular location a yearly repetition that can be calculated? I also need about 10 years of sunrises and sunsets. Is this possible to be calculated? $\endgroup$ Jun 5, 2023 at 14:12
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    $\begingroup$ Almanacs and other printed materials only have rise and set times for very select locations. They also only cover short periods of time (like 1 year). So software is your best bet. $\endgroup$ Jun 6, 2023 at 18:48
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    $\begingroup$ Yes, that's a property of almanachs. But I edited / expanded my answer with the comments here, also stressing this point. $\endgroup$ Jun 6, 2023 at 23:39

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