February has sometimes 28 days and others 29 why?

Answer 1

Because every four years there is a leap year. the reasoning behind this is that there is actually 365 and 1/4 days in a year or a complete rotation around the sun. To make up for this quarter of a day we lose every year they add an extra day at the end of february every four years. If they did not eventually summer would become winter an the seasons would be all messed up. We would go back a quarter of a day every year so in one hundred years the earth would be positioned in the same place around the sun on december first when it would actually be december 25. After a thousand years it would be snowing in july and we would be burning up in december.

Answer 2

A leap year is a year containing an extra day in order to keep the calendar year synchronized with the astronomical or seasonal year. For example, February would have 29 days instead of just 28. Seasons and astronomical events do not repeat at an exact number of days, so a calendar which had the same number of days in each year would over time drift with respect to the event it was supposed to track. By occasionally inserting an additional day or month into the year, the drift can be corrected.

The Gregorian calendar, the current standard calendar in most of the world, adds a 29th day to February in all years evenly divisible by 4, except for centennial years (those ending in -00), which receive the extra day only if they are evenly divisible by 400. Thus 1600, 2000 and 2400 are leap years but 1700, 1800, 1900 and 2100 are not.
Why?
The Gregorian calendar is designed to keep the vernal equinox on or close to March 21, so that the date of Easter remains correct with respect to the vernal equinox.
The vernal equinox year is currently about 365.242375 days long.
The Gregorian leap year rule gives an average year length of 365.2425 days.
This difference of a little over 0.0001 days means that in around 8,000 years, the calendar will be about one day behind where it should be.

Answer 3

In almost any four year period, you will have 3 Februarys with 28 days and one with 29 days. This is because it actually takes approximately 365.25 days for the earth to circle the sun (ie one year).

We could celebrate "new year" midnight one year, 6:00 am the next year, 12:00 mid day the next and 6:00 pm the next...then start the clcle again, but this would be confusing.

To simplify things, these quarter days are "saved up" and added to the forth year so it becomes 366 days long. This extra day is added to February.

This is not exact so adjustments have to be made on 3 Februarys in every four hundred years. 2000 had 366 days but 2100, 2200 and 2300 will only have 365 days. 2400 will have 366 days again.

Answer 4

February has 29 days on leap years (years divisible by 4, that is) and 28 days on other years.

Answer 5

The duration of one complete year is 365 + 1/4 days. But this 1/4 day is not counted. now adding these 1/4 days four times it will complete one complete day (1/4day+1/4day+1/4day+1/4day = 4/4 = 1day) so after every four year there is one day additional to 365 days i.e. 366 days. Now this 1 day is added in february and thus it becomes 29 days.

Answer 6

To make up for the actual time it take for the earth to go around the sun, it actually take 365 and a quarter days, so every four years we have a leap year and add a day to February!

Answer 7

To account for the fact that a year is actually 365 and 1/4 days long. So every fourth year we add an extra day to stay in sync.

Answer 8

It takes the Earth 365.2345 days to revolve around the sun, or roughly 365 and a quarter. So to make up for the lost day, every fourth year we add a day.

Answer 9

because the real calender is 365 and 1/4 days, well we cant do a 6 hour day so every 4 years we do 1 extra day.

Answer 10

because 29 days in a leap year. i think it might have something to do with daylight savings or do we just get that in australia? I think it is something to do with the seasons changing anyway?