51 days,1 year not in leap year in a fraction
Answers
Step-by-step explanation:
Calendars: Can a leap year ever have two leap days?
There are two different definitions of a "year" involved here. There's a solar year, the time it takes for the sun to return to its exact position in the sky (365.24219647 days) and the sidereal year, the time it takes for the stars to return to their exact positions (365.256363004 days). The difference is about 20 minutes.
Leap years are based on solar years, the time from equinox to equinox. That's of more interest to earthly events, since we organize our lives around the sun. If we used the sidereal year, we'd always know where the stars were, but after 13,000 years summer would come in January. After a mere century, we'd be a day and a half off; over the lifetime of the United States it would have a noticeable effect on planting times.
Instead, what we observe is that the sun moves with respect to the fixed stars in a 26,000 year cycle. It means that your zodiac sign drifts over time, and since year 1 we've drifted about a month. So your ancient horoscope system isn't merely hooey; it's not even the right hooey any more.
Sunrise on the equinox drifts from one "sign" to another over time. Now, it's rising in Aquarius on the vernal equinox. Remember "Age of Aquarius"? That's what that means.
We could use a leap year system to prevent the precession of the equinoxes, but it's of little interest to anybody except the astrologers. The astronomers, of course, care very much, but they use a whole different coordinate system to keep track of things.
Instead, we use the leap years to jiggle the sun into the right place. The solar year 365.2422 days can be seen as 365+.25-.01+.0022. So we have a leap year every .25 years (i.e. once every four years), subtract one every .01 years (i.e. we don't have one in the '00 years), and add in one every .0022 years (about 1 in every 400, which included 2000, when we had a leap year).
There's still a small creep of a day every 1/.0003 years (i.e. 3,000 years). That's somebody else's problem.
A sidereal year leap year would have to have extra leap years, rather than fewer. You could approximate 365.2564 as 365+.25+1/150, giving us an extra leap year every century and a half, which you could put anywhere you like (two leap days in one year, or an off-year leap year). You could have an alternating cycle that had two leap days in one year, then 150 years later an off-cycle leap year, then another doubling 150 years after that (since 150 doesn't divide evenly by four). The error would be 1 day in 3,750 years, clearly somebody else's problem. But nobody has any need for it, so they don't.