Questions of time

1)Find the duration from March 2008 to October 2008.

2)Find the duration from 1957 to2008.

3)Find the duration from 18 September 2007 to 5 December 2007.

4)A few groups of junior football teams were at a training camp from 14 October 2007 to 6 February 2008.How long were they at camp?

game about clock

A sundial is a device that measures time by the position of the Sun. In common designs such as the horizontal sundial, the sun casts a shadow from its style onto a surface marked with lines indicating the hours of the day. The style is the time-telling edge of the gnomon, often a thin rod or a sharp, straight edge. As the sun moves across the sky, the shadow-edge aligns with different hour-lines. All sundials must be aligned with the axis of the Earth's rotation to tell the correct time. In most designs, the style must point towards true celestial north (not the north magnetic pole or south magnetic pole). That is, the style's horizontal angle must equal the sundial's geographical latitude.
Unfortunately, it is common for inexpensive decorative sundials to have incorrect hour angles, and these cannot be adjusted to tell correct time.

did time is use for us????

time help us to wake up at morning...
time help us to now when we have do something....

THE BEGINNING OF TIME

The Egyptians were the first people who created a twenty-four hour day.  Time was a little bit different in those days.  The night was divided up into twelve hours, which were designated by the position of stars in the sky.  The day was divided into ten hours and a shadow clock was used to keep track of these hours.  The twilight hours were the hours before dawn and after sunset.

   The Egyptians thought they were the first to invent the shadow clock, but they were mistaken.  At the same time, the Chinese, Babylonians, Greeks and the Romans were using instruments to tell time.  Sundials were used in some of these groups, not because they work better, just because that's how they decided to tell time.

      After a while, the Egyptians and other ancient societies realized that the sun rose and set in different places in the summer and winter.  In fact, the sun never took the same course on any one day throughout the year!  They tried everything, until they realized that if they would just put the post of the sundial in at a special angle, it would work all year.  

TIME PAST.....

The measurement of time began with the invention of sundials in ancient Egypt some time prior to 1500 B.C. However, the time the Egyptians measured was not the same as the time today's clocks measure. For the Egyptians, and indeed for a further three millennia, the basic unit of time was the period of daylight. The Egyptians broke the period from sunrise to sunset into twelve equal parts, giving us the forerunner of today's hours. As a result, the Egyptian hour was not a constant length of time, as is the case today; rather, as one-twelfth of the daylight period, it varied with length of the day, and hence with the seasons. It also varied from place to place on the surface of the Earth. And of course, time as a measurable concept effectively ceased during the hours of darkness.

The need for a way to measure time independently of the sun eventually gave rise to various devices, most notably sandglasses, waterclocks, and candles. The first two of these utilized the flow of some substance to measure time, the latter the steady fall in the height of the candle. All three provided a metaphor for time as something that flows continuously, and thus began to shape the way we think of time.

Candle clocks

A candle clock

It is not known specifically where and when candle clocks were first used; however, their earliest mention comes from a Chinese poem, written in 520 by You Jianfu. According to the poem, the graduated candle was a means of determining time at night. Similar candles were used in Japan until the early 10th century.^[38]
The candle clock most commonly mentioned and written of is attributed to King Alfred the Great. It consisted of six candles made from 72 pennyweights of wax, each 12 inches (30 cm) high, and of uniform thickness, marked every inch (2.5 cm). As these candles burned for about four hours, each mark represented 20 minutes. Once lit, the candles were placed in wooden framed glass boxes, to prevent the flame from extinguishing.^[39]
The most sophisticated candle clocks of their time were those of Al-Jazari in 1206. One of his candle clocks included a dial to display the time and, for the first time, employed a bayonet fitting, a fastening mechanism still used in modern times.^[40] Donald Routledge Hill described Al-Jazari's candle clocks as follows:

The candle, whose rate of burning was known, bore against the underside of the cap, and its wick passed through the hole. Wax collected in the indentation and could be removed periodically so that it did not interfere with steady burning. The bottom of the candle rested in a shallow dish that had a ring on its side connected through pulleys to a counterweight. As the candle burned away, the weight pushed it upward at a constant speed. The automata were operated from the dish at the bottom of the candle. No other candle clocks of this sophistication are known.^[41]