Insights Measuring How Many Days Are in a Year - Comments

[Jim60]

Using that site again to count the days from 2000 June 21st 1 hour 48 minutes to 2025 June 21st 2 hours 42 minutes (summer solstice to summer solstice).

Totalled 9131.0375 SI days, divided by 25 years is 365.24150 SI days per year, minus this value from the average Tropical year of 365.24219 days is 59.616 seconds less.

 

[Jim60]

Using that site again to count the days from 2000 December 21st 13 hours 37 minutes to 2025 December 21st 15 hours 3 minutes (winter solstice to winter solstice),
Totalled 9131.05722224 SI days, divided by 25 years is 365.24239 SI days per year, minus the average tropical year of 365.24219 days from this tropical year of 365.24239 days is 17.18 seconds more.

 

[Jim60]

Wikipedia average Anomalistic year is 365.259636 days, but using that site again.
Perihelion Perihelion Anomalistic year
2000 Jan 3rd 5 hours 18 minutes- 2001 Jan 4th 8 hours 52 minutes 367.1486111 days
2001 Jan 4th 8 hours 52 minutes - 2002 Jan 2nd 14 hours 9 minutes 363.2201389 days
2002 Jan 2nd 14 hours 9 minutes- 2003 Jan 4th 5 hours 2 minutes 366.6201389 days
2003 Jan 4th 5 hours 2 minutes - 2004 Jan 4th 17 hours 42 minutes 365.5277778 days
2004 Jan 4th 17 hours 42 minutes - 2005 Jan 2nd 0 hours 35 minutes 363.2868056 days
2005 Jan 2nd 0 hours 35 minutes - 2006 Jan 4th 15 hours 30 minutes 367.6215278 days
2006 Jan 4th 15 hours 30 minutes - 2007 Jan 3rd 19 hours 43 minutes 364.1756944 days
2007 Jan 3rd 19 hours 43 minutes - 2008 Jan 2nd 23 hours51 minutes 364.1722222 days
2008 Jan 2nd 23 hours 51 minutes - 2009 Jan 4th 15 hours 3 minutes 367.6520833 days
2009 Jan 4th 15 hours 30 minutes - 2010 Jan 3rd 0 hours 9 minutes 363.3604167 days
2010 Jan 3rd 0 hours 9 minutes - 2011 Jan 3rd 18 hours 32 minutes 365.7659722 days
2011 Jan 3rd 18 hours 32 minutes - 2012 Jan 5th 0 hours 32 minutes 366.25 days
2012 Jan 5th 0 hours 32 minutes - 2013 Jan 2nd 4 hours 38 minutes 363.1708333 days
2013 Jan 2nd 4 hours 38 minutes - 2014 Jan 4th 11 hours 59 minutes 367.30625 days
2014 Jan 4th 11 hours 59 minutes - 2015 Jan 4th 6 hours 36 minutes 364.7756944 days
2015 Jan 4th 6 hours 36 minutes - 2016 Jan 2nd 22 hours 49 minutes 363.6756944 days
2016 Jan 2nd 22 hours 49 minutes - 2017 Jan 4th 14 hours 18 minutes 367.6451389 days
2017 Jan 4th 14 hours 18 minutes - 2018 Jan 3rd 5 hours 35 minutes 363.6368056 days
2018 Jan 3rd 5 hours 35 minutes - 2019 Jan 3rd 5 hours 20 minutes 364.9895833 days
2019 Jan 3rd 5 hours 20 minutes - 2020 Jan 5th 7 hours 48 minutes 367.1027778 days
2020 Jan 5th 7 hours 48 minutes - 2021 Jan 2nd 13 hours 51 minutes 363.2520833 days
2021 Jan 2nd 13 hours 51 minutes - 2022 Jan 4th 6 hours 55 minutes 366.7111111 days
2022 Jan 4th 6 hours 55 minutes - 2023 Jan 4th 16 hours 17 minutes 365.3902778 days
2023 Jan 4th 16 hours 17 minutes - 2024 Jan 3rd 0 hours 39 minutes 363.3486111 days
2024 Jan 3rd 0 hour 39 minutes - 2025 Jan 4th 13 hours 28 Minutes 367.5340278 days

2000 to 2025 average Anomalistic year 365.3336111110920 days

 

[mfb]

Where is the point in collecting all those numbers?

 

[Jim60]

I’m trying to find the average anomalistic year and the average tropical year.
Maybe I need more than 25 years?
Does anyone know of a data source that I can use?

 

[mfb]

Maybe I need more than 25 years?

Depends purely on the precision you want to achieve.

 

[Jim60]

It depends on how accurate the data is.
According to that site I’ve been using, Aphelion, Earths closes approach to the Sun will occur in 62.612 SI days on July 4th 16 hours 24 minutes UT.
What way could that be proved?

Sorry I meant, Earth will be furthest away from the Sun.

Note to self, must engage brain before posting.

And finally I hope I’ve got it right, its 61.42 SI days away on July the 4th 16 hours 24 minutes.

 

[mfb]

I merged your posts, you can edit your posts if you want to add something.

What way could that be proved?

There are databases keeping track of those dates.

 

[Jim60]

I merged your posts, you can edit your posts if you want to add something.There are databases keeping track of those dates.

Do you have a link?

 

[Jim60]

2000 to 2025 aphelion to aphelion
2000 July 3rd 23 hours 49 minutes - 2001 July 4th 13 hours 37 minutes 365.57500 SI Days
2001 July 4th 13 hours 37 minutes - 2002 July 6th 3 hours 47 minutes 366.590278 SI days
2002 July 6th 3 hours 47 minutes - 2003 July 4th 5 hours 40 minutes 363.078472 SI Days
2003 July 4th 5 hours 40 minutes - 2004 July 5th 10 hours 54 minutes 367.218056 SI Days
2004 July 5th 10 hours 54 minutes - 2005 July 5th 4 hours 58 minutes 364.752778 SI Days
2005 July 5th 4 hours 58 minutes - 2006 July 3rd 23 hours 10 minutes 363.758333 SI Days
2006 July 3rd 23 hours 10 minutes - 2007 July 6th 23 hours 53 minutes 368.029861 SI Days
2007 July 6th 23 hours 53 minutes - 2008 July 4th 7 hours 41 minutes 363.325 SI Days
2008 July 4th 7 hours 41 minutes - 2009 July 4th 1 hour 40 minutes 364.749306 SI Days
2009 July 4th 1 hour 40 minutes - 2010 July 6th 11 hours 30 minutes 367.409722 SI days
2010 July 6th 11 hours 30 minutes - 2011 July 4th 14 hours 54 minutes 363.141667 SI days
2011 July 4th 14 hours 54 minutes- 2012 July 5th 3 hours 32 minutes 366.526389 SI days
2012 July 5th 3 hours 32 minutes - 2013 July 5th 14 hours 44 minutes 365.466667 SI days
2013 July 5th 14 hours 44 minutes - 2014 July 4th 0 hours 13 minutes 363.395139 SI days
2014 July 4th 0 hours 13 minutes - 2015 July 6th 19 hours 40 minutes 367.810417 SI days
2015 July 6th 19 hours 40 minutes - 2016 July 4th 16 hours 24 minutes 363.863889 SI days
2016 July 4th 16 hours 24 minutes - 2017 July 3rd 20 hours 11 minutes 364.157639 SI days
2017 July 3rd 20 hours 11 minutes - 2018 July 6th 16 hours 47 minutes 367.858333 SI day
2018 July 6th 16 hours 47 minutes - 2019 July 4th 22 hours 11 minutes 363.225 SI day
2019 July 4th 22 hours 11 minutes - 2020 July 4th 11 hours 35 minutes 365.558333 SI days
2020 July 4th 11 hours 35 minutes - 2021 July 5th 22 hours 27 minutes 366.452778 SI Days
2021 July 5th 22 hours 27 minutes - 2022 July 4th 7 hours 11 minutes 363.363889 SI days
2022 July 4th 7 hours 11 minutes - 2023 July 6th 20 hours 7 minutes 367.538889 SI Days
2023 July 6th 20 hours 7 minutes - 2024 July 5th 5 hours 6 minutes 364.374306 SI Days
2024 July 5th 5 hours 6 minutes - 2025 July 3rd 19 hours 55 minutes 363.617361 SI Days
Total 9130.8375 SI days
2000 to 2025 Average year 365.2335 SI Days
Still nowhere near Wikipedia Anomalistic year of 365.259363 days.
Does anyone know how they calculated this year?

 

[Jim60]

Think I’ve figured out how Wikipedia got 365.256363004 SI days for the Sidereal year?
Earths semi-major axis a = 1.4959974465490E+11 Metres.
Gravitational constant G = 6.67408E-11 Newton Metres squared / kilogram square
Suns mass M1 = 1.98855E+30kg
Earths mass M2 = 5.97237E+24kg
T = 2*PI()*SQRT(a^3/G*(M1+M2))
Orbital period T = 31558149.76354540 SI seconds