What is the length of day time for the summer?

Answer 1

The planet's rotational period is the only thing that determines the length of one day.

(mostly - it also is dependent on how fast the planet orbits the sun. If it orbits quickly, the "day" will be measurably less than the time for one full rotation.)

Answer 2

The month is based on the amount of time it takes for the moon to orbit the earth.

Answer 3

One year is equal to the time it takes the Earth to complete one orbit around the Sun, which no-one is responsible for. In terms of the Calendar, the last time the system was changed was in 1582 by Pope Gregory XIII, who shortened that year by ten days and decreed that in future three more days should be taken out of every four hundred years. It took several centuries for his changes to be accepted around the world. The current Pope is Benedict XVI.

Answer 4

There are at least 3 meanings of the word "day":

1.) If by "day" you refer to the rotation period of the Earth with respect to the Sun, that's the solar day. It has natural variations during the year, so we use the average, called the "mean solar day". It's exactly 24 hours, but see below

for a slight amendment to this.

Incidentally, the Earth's solar day has increased in length over time. The length of one day, when the Earth was new about 4.5 billion years ago, was about six hours as determined by computer simulation. It was 21.9 hours 620 million years ago as recorded by rhythmites (alternating layers in sandstone). This phenomenon is due to tides raised by the Moon which slow Earth's rotation.

2.) The "SI " (the International System of Units) definition. The "SI second" was defined according to measurements of the length of the mean solar day in the early part of the 19th century (24 hrs x 60 min x 60 secs = 86,400 seconds per day). The length of the mean solar day has increased and is now about 86,400.002 SI seconds. It continues to increase by about 1.7 milliseconds per century. The Earth's rotation speed varies in an irregular manner over a period of several years, but overall it is slowing. The modern SI second is defined using "atomic clocks" and doesn't depend on the Earth's motion at all.

In "SI", a "day" is defined as exactly 86,400 "SI" seconds. This is the "day" of our 24 hour clocks. This day is shorter than the actual average solar day by about 0.002 seconds. For this reason, we have occasionally added a leap second to our clock to keep it more closely synchronized to the Earth's rotation. This policy is currently under review and we may soon cease to add leap seconds if it is determined that the inconvenience of adding leap seconds is greater than the inconvenience of not adding them.

3.) Then there is the, sidereal day which is the rotation period relative to the distant stars. Its J2000 mean value is 23 hours 56 minutes 4.090530833 seconds. (Sidereal is from Latin: sidus = star, genitive case: sideris.)

There's actually another, related definition, called a "stellar day", but I'm sure that's more than enough detail already, for most people.

Answer 5

That depends on your latitude. In the tropics, day length is not especially affected by the seasons. In the Arctic, the Sun never sets on the summer solstice, and in "temperate" latitudes, anything from 13 to 23 hours of daylight can be expected.

Answer 6

That depends on the latitude. North of the Arctic Circle, the day length is 24 hours; the Sun doesn't go down at all. At the North Pole, the Sun rises on March 21 and sets on September 21, for a "day" that is 6 months long.

Answer 7

Yesterday was the winter solstice in the northern hemisphere, and the days will lengthen by a few seconds per day right away. We probably won't notice the change for two or three weeks. After that, it will be easily noticeable.

Answer 8

There are two solstices every year.

In the northern hemisphere, the solstice that's always within a day of June 21

is called the Summer one. In the Southern Hemisphere, it's the one within a day

either way of December 21.

Answer 9

There are two equinoxes on the map of the stars ... points that the sun

passes in its annual (yearly) trip through the stars. It passes one of them

on March 21 and the other one within a day or two of September 21.

Answer 10

The solstices generally occur on June 21 and December 21 each year, although that date can vary a day either way depending on the cycle of leap years.

The equinoxes are generally on March 21 and September 21, and ditto.