Should 2800 be a leap year?

[DoomYoshi]

This is an important decision. That will be the year the Gregorian calendar goes out of sync if it is a leap year. However, people can't just arbitrarily mess with the leap year formula all willy-nilly. That's why we have standards.

[jusplay4fun]

There is a fomula and the year 2800, since it is divisible by 400, is a leap year.

JP

https://en.wikipedia.org/wiki/Leap_year

In the Gregorian calendar, the standard calendar in most of the world, most years that are multiples of 4 are leap years. In each leap year, the month of February has 29 days instead of 28. Adding one extra day in the calendar every four years compensates for the fact that a period of 365 days is shorter than a tropical year by almost 6 hours.[4] Some exceptions to this basic rule are required since the duration of a tropical year is slightly less than 365.25 days. The Gregorian reform modified the Julian calendar's scheme of leap years as follows:

Every year that is exactly divisible by four is a leap year, except for years that are exactly divisible by 100, but these centurial years are leap years if they are exactly divisible by 400. For example, the years 1700, 1800, and 1900 were not leap years, but the years 1600 and 2000 were.[5]

Over a period of four centuries, the accumulated error of adding a leap day every four years amounts to about three extra days. The Gregorian calendar therefore removes three leap days every 400 years, which is the length of its leap cycle. This is done by removing February 29 in the three century years (multiples of 100) that cannot be exactly divided by 400.[6][7] The years 1600, 2000 and 2400 are leap years, while 1700, 1800, 1900, 2100, 2200 and 2300 are common years. By this rule, the average number of days per year is 365 + ​1⁄4 − ​1⁄100 + ​1⁄400 = 365.2425.[8] The rule can be applied to years before the Gregorian reform (the proleptic Gregorian calendar), if astronomical year numbering is used.[9]

[DoomYoshi]

So you'd rather follow the formula than have the date be correct?

[tzor]

Who cares, we will be using star dates by that time.

[jusplay4fun]

The date will be correct, IF you follow the "formula"

JP

So you'd rather follow the formula than have the date be correct?

[DoomYoshi]

The date will be correct, IF you follow the "formula"

JP

So you'd rather follow the formula than have the date be correct?

Ok, so formulas are infallible. That is good to know.

But seriously the formula is off by 27 seconds per year, and that 27 seconds will catch up to us after 2800. If it wasn't a leap year we'd have a long way to go before anyone had to worry.

I knew this would get a lot of backlash, which is why I'm starting now.

[patches70]

Something should be done about this, it's Y2K all over again!

[jusplay4fun]

Seriously, did you ever hear of the Leap Second?

Think of the SIgnificance, without the leap second: 27 seconds off in 782 years. I agree, we may be on Star Date (time) by then. (I cannot recall who posted that.)

JP

The date will be correct, IF you follow the "formula"

JP

So you'd rather follow the formula than have the date be correct?

Ok, so formulas are infallible. That is good to know.

But seriously the formula is off by 27 seconds per year, and that 27 seconds will catch up to us after 2800. If it wasn't a leap year we'd have a long way to go before anyone had to worry.

I knew this would get a lot of backlash, which is why I'm starting now.

[DoomYoshi]

A leap second is for something different though. Those are for keeping the atomic clocks lined up with real clocks as the earth can slow down in its rotations.

It's not 27 seconds off in 782 years. It's 27 seconds off per year. (when comparing the formula from the Gregorian calendar to the Tropical year, which may not be your preferred definition of a year). This is due to the formula in calculating leap years.

[jusplay4fun]

You were unclear about what the 27 seconds was about. I made an assumption and asked for clarification.

I think your 27 seconds per year refers to the difference between the solar day and the sidereal day.

JP

A leap second is for something different though. Those are for keeping the atomic clocks lined up with real clocks as the earth can slow down in its rotations.

It's not 27 seconds off in 782 years. It's 27 seconds off per year. (when comparing the formula from the Gregorian calendar to the Tropical year, which may not be your preferred definition of a year). This is due to the formula in calculating leap years.

[mookiemcgee]

It won't matter, we will all be dead... And mankind will be working on a mars calendar since all life on earth will have done extinct and we will have moved onto to a new kingdom.


(or the rapture will have happened)

[DoomYoshi]

You were unclear about what the 27 seconds was about. I made an assumption and asked for clarification.

I think your 27 seconds per year refers to the difference between the solar day and the sidereal day.

No, it's the difference between a tropical year and the year as calculated by Gregorian calendar.

A Gregorian year is 365 + leap year every 4 years (.25) - leap year every 100 years (-.01) + leap year every 400 years (.0025) for a total of 365.2425 days.
A tropical year is 365.24219 (this is an average!). This is a difference of .00006 which is actually just over 5 seconds, so my math was off earlier.

A sidereal year is actually longer than the Gregorian year, but less important since the relation to the sun determines our seasons, not our relationship to any fixed point outside our solar system.

[jusplay4fun]

so it is 5 seconds and NOT 27 seconds?

JP

You were unclear about what the 27 seconds was about. I made an assumption and asked for clarification.

I think your 27 seconds per year refers to the difference between the solar day and the sidereal day.

No, it's the difference between a tropical year and the year as calculated by Gregorian calendar.

A Gregorian year is 365 + leap year every 4 years (.25) - leap year every 100 years (-.01) + leap year every 400 years (.0025) for a total of 365.2425 days.
A tropical year is 365.24219 (this is an average!). This is a difference of .00006 which is actually just over 5 seconds, so my math was off earlier.

A sidereal year is actually longer than the Gregorian year, but less important since the relation to the sun determines our seasons, not our relationship to any fixed point outside our solar system.

[DoomYoshi]

Well, timeanddate.com says 27 seconds but I calculated myself at 5 seconds.
https://www.timeanddate.com/date/perfect-calendar.html

Today's Gregorian calendar uses more elaborate leap year rules, making it far more accurate. However, it is not perfect either. Compared to the tropical year, it is 27 seconds too long, so it is off by 1 day every 3236 years.

[jusplay4fun]

Interesting; thanks for sharing. I learned more about calendars. That, sir, is a compliment. Well Done..!

JP4Fun

Well, timeanddate.com says 27 seconds but I calculated myself at 5 seconds.
https://www.timeanddate.com/date/perfect-calendar.html

Today's Gregorian calendar uses more elaborate leap year rules, making it far more accurate. However, it is not perfect either. Compared to the tropical year, it is 27 seconds too long, so it is off by 1 day every 3236 years.