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Should there be a mention that on other planets the year is different? --Daniel C. Boyer

It does seem to now: perhaps editted since your undated comment? As it looks out of date, lets agree if you do not repeat it within a month of this query I'll do a clean-up (talk)--BozMo 22:25, 9 May 2004 (UTC)

the same is here: http://www.sciencedaily.com/encyclopedia/year :P

Can some physics guru out there calculate the shorting of the year due to the mass loss of the sun over time. Because the rate is so gradual I do not expect there to be non equillibrium effects. Assuming a circular orbit, the radial orbit change(accelleration) should be able to be calculated from a force balance of the centripetal and gravitational forces. This radial change will give a new period since the kenetic and potential energy is related in orbital mechanics. I'm currious about the change in the period over time, since it has implications on the age of the earth, and the rate of energy output of the sun.

This also has an impact on the alinement of planets the ancients saw when the looked up at the sky. Does anyone know if celestia takes this into account when calculating historical star chart data?

Contents 1 Block Request for Admins 2 Seasonal Year edit 3 Astronomical Year section reformatting 4 Calendar repetition 5 Oriental great year 6 gigayear 7 Re Gaussian Year 8 Draconic years instead of 365 day year 9 Weeks 10 orbital chaos 11 Merge from Annum 12 Too technical too quickly 13 Question on being Reverted 14 365.242199 days in a year 15 365.44 days

[edit] Block Request for Admins

24.110.43.34 was trolling this page (length of a year changed in all instances to aprox 100 days) and when I checked his edit log, all edits were vandalism, as such I request that this user is blocked by an Admin —Preceding unsigned comment added by 75.157.213.174 (talk) 21:47, 10 January 2009 (UTC)

[edit] Seasonal Year edit

I removed "the hottest day of the year" as an example starting point for a seasonal year because it is not a definite/conclusive starting point in that there could always be a unexpected hotter day later on. All the other given examples have definite starting points, for instance when flowers start to bloom, you know that's the start of that flowers "season". I also added "the first scheduled game of a certain sport" to throw in a man-made seasonal year example into the mix. Comments?

[edit] Astronomical Year section reformatting

I added bullets to the listings of the astronomical years because I think it looks better in general and breaks up the different types for easier reading. I don't know if doing this is within Wiki-policy, anyone care to comment or take a vote on it?

[edit] Calendar repetition

I think it would be nice to have information regarding calendar repetition, that is, is there a way to tell when is this year's calendar going to be repeated? For example, 2005 is a Common year starting on Saturday. When in the future will the 2005 calendar be repeated, like August 12 will be friday and all other days will be the same week day as in 2005? When in the past was it repeated like that?

I've never heard of any such calculations, just wondering if anybody has.

You cite a wikipage that already lists the years that have identical calendars, so I gather you don't just want to know what years are identical, but how to determine them by calculation. Unfortunately, I don't know of any such calculation. I can only mention that whatever the retitions are, they must repeat on a 400-year cycle. — Joe Kress 18:54, August 12, 2005 (UTC)

All solar calendars with a leap year every four year and a 7-day-week repeat in principle every 28 years (=4x7). But a additional leap year interrupts this so-called solar cycle. Thus Gregorian calendar years 1801, 1829, 1857, 1885 began with a Thursday, like 1901, 1929, 1957, 1985 with a Tuesday. There are exactly 20871 weeks in a Gregorian 400 years cycle, so it well repeats after each full cycle. All in all, there exist only 14 calendars. 7 for common years, 7 for leap years.
--Peter 2005 12:51, 14 August 2005 (UTC)

To find out when the next Gregorian calendar year occurs that is identical to the current one, you need to know the number of the current year (e.g., 2008). Calculate three quantities: the remainder after dividing by 4 (call it Q), the remainder after dividing by 100 (call it C), and the remainder after dividing by 400 (call it M).

For all the years from 1901 to 2071, all you need to know is Q.

• If Q equals 0, the next identical calendar is in 28 years.
• If Q equals 1, the next is in 6 years.
• If Q equals 2 or 3, the next is in 11 years.

The above also holds for all years where M is greater than 300 or equal to zero. It holds for most other years as well, the only exceptions being:

• If C is greater than 71 and Q equals zero, then the next is in 40 years.
• If C is equal to 90, 91, 97, or 98, the next is in 12 years.
• If C is equal to 94, 95, 99, or zero, the next is in 6 years.

Rwflammang (talk) 18:41, 28 October 2008 (UTC)

The Gregorian calendar includes lunar as well as solar aspects (although the lunar aspects are usually only used for religious purposes). I doubt Rwflammang's technique finds the next year that is identical in both the solar and lunar sense. --Gerry Ashton (talk) 18:56, 28 October 2008 (UTC)

It certainly does not. It simply finds the next time one of the 14 calendars mentioned by Peter 2005 is repeated, which is all that was asked for. Rwflammang (talk) 14:43, 29 October 2008 (UTC)

[edit] Oriental great year

The following statement was added to the article by 71.36.34.14. I have moved it here because I have never heard of it even with my fairly extensive knowledge of Chinese astronomy and Creation myths, and no citation is given. It is doubtful that it is the source of the Western 24-hour day because the Chinese used a clock with twelve double hours, not one with 24 hours. The standard explanation for the Western 24-hour clock is that the Egyptians used 24 seasonal hours (12 daylignt and 12 nighttime).

Oriental astronomy puts the length of one Great Year at 24,000 years comprised of one ascending cycle of 12,000 years and one descending cycle of 12,000 years. Some scholars believe this may be the original basis for the current system of daily time; a 24 hour day with 12 hours of increasing light (AM) and 12 hours of increasing darkness (PM).

A citation is needed before it can be added to the article. Don't use the weasal words "some scholars". Cite which scholar or scholars.

— Joe Kress 01:00, 22 November 2006 (UTC)

[edit] gigayear

Why is gigayear redirected here if theres nothing about it? —The preceding unsigned comment was added by 195.194.178.251 (talk) 11:19, 12 January 2007 (UTC).

Likely because a gigayear is just 10E9 years and is no more special than 2 years, 3 years or even one year. —Preceding unsigned comment added by 90.185.74.159 (talk) 14:50, 30 October 2009 (UTC)

[edit] Re Gaussian Year

The present Wiki section on "Gaussian Year" is not adequate (the length is a result; it is not the definition).

I think it needs a "1 A.U." or equivalent, and a reference to the Sidereal Year.

The definition in http://www.kayelaby.npl.co.uk/general_physics/2_7/2_7_2.html should be reliable.

82.163.24.100 12:08, 29 January 2007 (UTC)

TP: I don't see anything factually wrong in that section; you are correct that the year length is a derived value, but this page does not imply otherwise. What exactly do you object against? —The preceding unsigned comment was added by Tom Peters (talk • contribs) 21:33, 29 January 2007 (UTC).

OK, I now see that, while the (Newtonian) gravitational constant G is a constant of the universe, the Gaussian constant is parochial and is governed by the orbit that the Earth happens to have - it could be called the Earth's Gaussian Gravitational Constant.

I still prefer the Kaye&Laby statement as a description of the Gaussian Year, but it is less direct as a definition.

I think that more people will be familiar with SI units than with Astronomers' units.

In "Calendar year", the day is the (mean) solar day, defined by light-and-dark, of 86400-plus-a-bit SI seconds (the bit represents leap seconds). The Julian Year apparently uses the same unit. The Sidereal Year is given explicitly in SI seconds.

The Gaussian Year, however, being dependent solely on the Gaussian constant which is a fixed value not dependent on SI, seems at first to be in astronomers' units; but Kaye & Laby says that astronomers' seconds are SI seconds.

So : in the Year page, I now think that, for the avoidance of doubt, it would be well :-

1. to mark every expressed duration as "mean solar days" or "SI days" or whatever it happens to be;
2. to mark all exact values with "exactly" or similar, and all approximate values with a numerical uncertainty or with "approximately" or similar (the Gaussian year could be put as "exactly 2π/k").

82.163.24.100 13:19, 30 January 2007 (UTC)

[edit] Draconic years instead of 365 day year

Much better solution would be adopting septenary 343-day year derived from draconic year defined here: http://en.wikipedia.org/wiki/Year#Draconic_year because it has nothing to do with satanic 6*6*10, and is defined as God's 7 days *7 weeks *7 seasons. God purposedly instituted draconic year in Solar System to give chance of avoiding satanic multiples in time measurements.83.19.52.107 10:24, 15 March 2007 (UTC)

A "solution" implies a problem or purpose. If the purpose is to appease the religious nutjobs, I guess 343 has its uses (until someone comes along who says 343 is satanic); if the purpose is to keep track of the seasons, better to stick with the tropical year God gave us. If God wanted us to use 343-day years, why establish a 346-day cycle and make it so far from obvious? —Tamfang 05:35, 3 April 2007 (UTC)

A comprehensive proof of evilness of these unholy numbers such as 6,60,90,180,270,360,666,3600,6666, which refuses to be completed up to multiples of holy seven is placed here: [1] Thus better use purely septenary system. Both draconitic and tropical year are not ideal 360 and 343 days, but their approximations such as 365.24218967 and 346.620075883 days. That proves that God provided us possibility of choosing between blessing and curse (Deuteronomy 30:19), namely between God's 343-day septenary year and between devil's 360-day sexagesimal year. 346 excess above 343 by 3 days, and 365 excess above 360 by 5 days, making draconic year closer to God's 7*7*7=343, than tropical year to devil's 6*6*10=360. More about full septimalization of all units here: [2] Only pharisee can apply satanic etiquette to God's 7*7*7=343. 83.19.52.107 08:21, 10 April 2007 (UTC)

Are honeybees satanic too, with their hexagonal cells? —Tamfang 21:51, 3 May 2007 (UTC)

I see that some prefer 7, so I'll chime in with a fact that might be found a little more appealing as regards the current system (and previous Julian): (365+1/4)^4=17797577732+7^2/2^8. This has a simpler relative you may like less (but there is a seventh power): (365+1/4)^2=3^7*61+9/16.Julzes (talk) 06:45, 26 May 2009 (UTC)

Honeybees are domestified wasps, and all dangerous animals came after original sin. Before original sin they yet didn't existed. 83.19.52.107 07:52, 23 May 2007 (UTC)

[edit] Weeks

The article states that the Julian calender has 365.25 days per year but something is not right. How can there be 52 weeks in a year times seven days a week which equals 364 days? Is it safe to conclude that there are really 52.xxx weeks in a year, but we just round down to make it an even number ? —Preceding unsigned comment added by 70.17.198.177 (talk) 06:47, 18 February 2008 (UTC)

Anyone who states that there are 52 weeks in a year is not being precise. The Julian year has either 365 or 366 days thus 52 weeks and either one or two extra days beyond that number of whole weeks. But these two values mean that a single value for the number of weeks in a year (52.xxx) is possible only as an average value. — Joe Kress (talk) 08:33, 19 February 2008 (UTC)

[edit] orbital chaos

The Earth orbit varies by a chaotic way, but in a interval quite more reduiced than the orbits of the nearest planets.

What does this mean? —Tamfang (talk) 06:26, 20 May 2008 (UTC)

Can you please tell us where in the article that text is? Karl (talk) 10:24, 20 May 2008 (UTC)

Search the article for the word 'chaotic': it's in Year#Variation_in_the_length_of_the_year_and_the_day. —Tamfang (talk) 22:51, 23 May 2008 (UTC)

[edit] Merge from Annum

It seems to me that Annum is just a scientific synonym of "year", and therefore Annum should just redirect here, with any of its salvageable content moved here. The current article reads to me like original research, or at least an original synthesis, and the listed references don't really support the main body of the article.--Aervanath lives in the Orphanage 04:31, 11 July 2008 (UTC)

The listed refs went through a revision process, so the links were broken when ISO 31-1:1992 was replaced by ISO 80000-3:2006 recently. I haven't yet had a chance to review the new issues. Likewise the implementing NIST pub was revised in 2008. The merge may be a good idea, we'll have to give it some consideration. But simply replacing the page with a redirect didn't cut it. LeadSongDog (talk) 05:53, 11 July 2008 (UTC)

Fair enough. The BOLD, revert, discuss cycle is working well in this case. But you haven't yet addressed my concerns about OR and SYN.--Aervanath lives in the Orphanage 22:25, 11 July 2008 (UTC)

The existing Year is completely unreferenced. The existing Annum is a little better, though admittedly not much. I'm fairly confident the bulk of either can be supported in available refs. Were there specific statements that you see as OR or as SYN? If so, don't hesitate to tag the cases that trouble you most.LeadSongDog (talk) 06:11, 14 July 2008 (UTC)

I subscibe the proposed merge of this page with the page for the Year. SAE1962 (talk) 11:39, 12 December 2008 (UTC)

[edit] Too technical too quickly

I read this article with a hope to better understand what's happening astronomically that causes what we experience as seasonal variation. I soon got bogged down in too many similar-sounding definitions of a year and links to other articles (like the one on precession) which also failed to make things any clearer.

It seems to me that the historically first and lay definition of the year involves this cyclic change of climate. It would seem natural to lead into the article with a discussion of this definition of a year, so that readers are grounded in something they find familiar. I'm sure there's an astronomical correlate of this "year of the seasons" I'm talking about, although from the article I can't tell what it is (probably the tropical or sidereal year). This should be the first concept to be introduced and other definitions of a year should follow from there.

I think that would make the article far more useful, particularly to people with no background in astronomy. I hope this suggestion helps.

Ben Arnold (talk) 10:28, 17 May 2009 (UTC)

Yes, the cycle of seasons is the tropical year. —Tamfang (talk) 02:15, 18 May 2009 (UTC)

[edit] Question on being Reverted

I tried adding "The experienced average approximate year is 365.25 days." before the fact that 400 Gregorian years make an integral number of weeks near the end of the article. It was as a remark that we all happen to live near the year 2000 intended with humor in the way I assume all of the overly specific counting is. Should I undo?Julzes (talk) 06:03, 26 May 2009 (UTC)

I don't think the goal here should be humor, especially of the kind that isn't humorous. Ilkali (talk) 08:55, 26 May 2009 (UTC)

Are you saying "in the experience of people living between 1900 Mar 1 and 2100 Feb 28, the average year-length is 365.25"? With a bit of effort I can see some humor in that, but not enough to justify going out of one's way to mention it in the article. —Tamfang (talk) 23:45, 27 May 2009 (UTC)

That was a part of it.Julzes (talk) 06:17, 29 May 2009 (UTC)

[edit] 365.242199 days in a year

I'm surprised there is no mention on the page, the universally accepted estimate of the number of days in a year. The article should at least mention it somewhere, does anyone else second that? --Thelazyleo (talk) 22:18, 2 August 2009 (UTC)

There are many kinds of years. What kind of year is 365.242199 days and what reliable source says this estimate is universally accepted? --Jc3s5h (talk) 22:23, 2 August 2009 (UTC)

The mean tropical year according to Simon Newcomb was 365.24219879 days at J1900.0. Needless to say, the approximation 365.242199 days is quite old. The J2000.0 value of the mean tropical year is already in the article alongside values for the sidereal, anomalistic, and draconic years. — Joe Kress (talk) 05:37, 3 August 2009 (UTC)

[edit] 365.44 days

I was recently informed that some authorities assert that one year is 365.44 day, instead of 365.25. I did a quick Google search on the two terms but was unable to find any intelligible information corroborating or even elaborating on this assertion. If anyone knows something about this, please provide information. __meco (talk) 12:42, 14 August 2009 (UTC)

Sounds like bogus to me. The only lengths of a tropical year I have heard of are the refinements of the original Julian year length -- i.e. close to (and never larger than) 365.25 days (whatever a day is). —Preceding unsigned comment added by 90.185.74.159 (talk) 14:58, 30 October 2009 (UTC)