Skip to comments.Why Do We Need Leap Days?
Posted on 03/03/2012 1:22:50 AM PST by U-238
Most years, the calendar hops straight from Feb. 28 to Mar. 1. But in almost all years whose numerical value is divisible by four, such as 2012, an extra "leap day" gets tacked on the end of the second month. Cue, today's date: Feb. 29.
The extra day must be added to every fourth calendar year in order to keep our Gregorian calendar synchronized with actual astronomical measures of the passage of time. According to the National Institute of Standards and Technology (NIST), the length of Earth's year as in the time it takes for the planet to complete one revolution around the sun is not a clean 365 days, but rather 365.2422. Adding an extra day to one-fourth of calendar years compensates for the buildup of partial days.
However, because the astronomical year isn't exactly 365.25 days long, but a hair shorter, the normal leap year schedule is a slight over-compensation. To scale back the full-day leaps and keep the calendar right on track, some century years (years with double zeroes at the end) are not leap years. The rule dictates that only century years which are divisible by 400, such as the year 2000, contain leap days. The numbers 1900, 1800 and 1700 aren't divisible by 400, and so those years were not leap years.
Altogether, the 400-year leap year cycle ensures that Earth is as close as possible to the same point in its orbit in consecutive calendar years. Any further errors that accumulate are corrected when needed through the addition of a leap second onto the last minute of either June or December. During leap seconds, the Coordinated Universal Time follows the sequence 23h 59m 59s - 23h 59m 60s - 00h 00m 00s.
(Excerpt) Read more at lifeslittlemysteries.com ...
I remember reading in some old history books the notation (O/S) meaning “Old Style” for a given date in colonial history. I don’t think historians bother with it any more.
This girl doesn’t understand leap years.
(warning: bad language)
The Romans started their civil year on March 1, not January 1. That's why September, October, November, and December have names deriving from the Latin for seven, eight, nine, and ten -- they were originally the seventh, eighth, ninth, and tenth months.
February was the short month tacked on at the end of the year because there weren't 30 or 31 days left to fill out a full month.
So women like Sandra Fluke can get a date.
We need Leap Year now so that we have to put up with Black History month for an extra day every 4 years.
Because the orbital period of the earth around the sun is about 365.2564 days and the rotational period of the earth is, by definition(with some variation) 24 hours. Point out the connection please.
Try this answer: If we did not do the correction, the calendar would run backward after 365 years. ROFLMAO
A "day," for example, is a measure of real time -- as is a "year." But the notion that a "year" begins and ends at the exact start/finish of a "day" is purely a human construct.
A "month" is loosely based on lunar cycles, but there is nothing that ties months directly to days and years, either.
A solar year (also known as a tropical year), for general purposes, is the length of time that the Sun takes to return to the same position in the cycle of seasons, as seen from Earth.
Sidereal time, the amount of time required for the earth to make a complete rotation around its axis is 23 hours, 56 minutes and four seconds (23:56:04) instead of 24 hours (24:00:00)
A leap year (or intercalary or bissextile year) is a year containing one additional day (or, in the case of lunisolar calendars, a month) in order to keep the calendar year synchronized with the astronomical or seasonal year.
When I was a kid, I read somewhere that the reason a year is such a screwy number is explained biblically. In the Bible there are passages, but I can only remember one, where an Israeli general prayed to God that night wouldn’t occur during a batlle, because then the enemy would be able to flee. God obliged and kept the sun from setting until the battle was done. TDon’t know if that’s why we have an extra day, but it works for me.
Well, that’s a different argument than the classical “Cosmic Watchmaker” argument. Still, I think it’s flawed. You are assuming the “watchmaker” intended the gears to match up in the way that you would expect or prefer. I can see no solid logical basis for making that assumption.
Exactly. Expecting them all to line up is just pure human conceit.
Now, if you are a Christian, you could try to make an argument from Genesis, about God setting the lights in the heaven for us to measure the times and seasons, and then wonder why they are not aligned more perfectly in order to facilitate that. If you want to make that argument, though, then you already have to accept the proposition of the Biblical God at work, and then you’d also have to accept the proposition that God’s will is not always comprehensible to us, so your argument would be self-defeating.
If the analogy is to watch where the gears match up precisely, my expectation that the rotation and the orbit match precisely us a reasonable, even necessary one. I cannot explain the obvious any further.
Some Creationists argue that perhaps, as a consequence of the flood catasphrophe, or maybe when the “world was divided” at the time of the Tower of Babel, the Earth could have lost some of its mass. That would have affected the rate of spin and the velocity of the Earth and changed the length of days and years.
Not something you can prove through Scripture, but it would be an interesting correlary to how man became flawed, with shorter and shorter lifespans after the fall, if the Earth itself became flawed too.
Well the Watchmaker analogy, as it is posited, has nothing to do with the gears of a watch related to the connection between days and years on Earth.
As for your version of it, it’s just a conceit. You are looking for the gears to sync up in the way that you would expect, but there is no objective reason why that should be the case. Every planet has different day lengths and year lengths, some radically different than ours. The whole system keeps spinning along, but you want there to be some perfect correlation between days and years in nice round numbers, in a manner that you define, and when you don’t find that, you’re basically saying that you have won an argument. In reality, all you’ve done is set up a straw man and take that straw man down. It’s a flawed argument to begin with, so it means nothing at all if you are able to negate it.
This is getting tiresome. There is no connection between the rotation of the earth and its orbit. That was my point. The two events are unrelated and any analysis of the two phenomena points to randomness rather than design. Period
The connection would be the mass. But it seems the real objection you have is the comparison to a watch.
“The two events are unrelated and any analysis of the two phenomena points to randomness rather than design. Period”
Now you’re resorting to circular argument. You can only say it points to randomness if you accept as a given that there should be a correlation between them if there is a designer. You have offered no argument as to why we should expect there would be, you just assume that, apparently because it suits your argument.
You argument, condensed, boils down to: “If there was a designer, the days and years should be in sync. The days and years aren’t in sync, therefore, there is no designer.” That is textbook circular reasoning, I hope you can see that.
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