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(3) It is easy (2) to understand the calendar (1) we use today. (1) It was not always so easy. (1) People (6) had to try (5) for thousands of years (4) before they knew (3) how to put together (2) days, weeks, months, and years. More than 2,000 years ago, (2) scientists in Egypt (3) made a calendar. (4) There were (1) ten days in a week, (2) three weeks in a month, and (3) twelve months in a year. (1) This calendar (3) showed a way (2) to count weeks and months, (4) but (5) it was not scientific. (3) It does not matter (2) how many days are (1) in a week, or in a month; (4) any number (5) can be used. (1) No one, however, (4) can decide (2) how long a day or a year (3) should be. (1) A day (4) is the exact length of time it takes (3) the earth (2) to turn around one time (1) A year (4) is the length of time (3) the earth takes (2) to travel around the sun one time. (1) The Egyptians (3) did not think (2) about these scientific facts. (1) For them, (2) 12 of their 30 day months (3) made a year, (4) but 360 days (5) do not make a full year. (2) What did they do (1) about this problem? (1) They (3) made a five-day holiday (2) at the end of each year. (1) But (2) even adding five holidays (4) did not make (3) the Egyptians' yearly calendar right. (3) It takes the earth (2) a little more than 365 days (1) to travel around the sun. (1) To be exact, (2) it takes 365 days, 5 hours, 48 minutes and 46 seconds. (1) For a long time (2) people did not add (3) these extra hours and minutes and seconds. (1) It (4) was like (3) using a watch (2) that runs slow. (1) The Egyptian calendar (3) was slower (2) than the exact sun year. (1)In four years (2) it (3) was about a day behind; (4) in forty years (5) the calendar (8) was 10 days (7) (a full Egyptian week) (6) behind the sun. (1) Many years later in Rome, (a) Julius Caesar (3) tried to fix the calendar. (3) He thought (1) that a year (2) should be 365 days and 6 hours long. (1) He (3) added an extra day (2) every four years. (1) The year with an extra day (2) is called leap year. (1) The year (2) is really, (3)365 days, 5 hours, 48 minutes and 46 seconds long. (1) Julius Caesar’s calendar (2) was almost twelve minutes too fast. (1) Twelve minutes is not much, (2) but by the year 1582 (6) scientists showed that (3) the calendar (5) was about 10 days faster (4) than the sun. (1) Pope Gregory XIII (2) wanted to make (3) a better plan. (3) It was easy (2) to take 10 days away (1) from the calendar. (1) This (3) made it right (2) with the sun again. (4) There was still a problem: (3) how to keep the calendar right (2) in the future, (1) year after year. (1) Scientists (2) tried one way, (3) and then (4) they tried another.(1) Finally, (5) they decided (4) to continue to have (3) every fourth year (2)as a leap year.(1) Then (3)they solved the problem of (2) the calendar going too fast. (1) They (44) made a plan (3) to take out three days (2) every 400 years. (2) A year ending in 00 is (3) not a leap year (1) unless it can be divided evenly by 400. (1) The year 1600 (2) was a leap year (3) but (4) 1700, 1800 and 1900 were not. (1) The year 2000 (2) was a leap year. (1) This (3) is the plan (2) we use now. (2) Our calendar, (1) named for Pope Gregory, (4) is called (3) the Gregorian Calendar. (1) It is not quite exact. (1) It (4) is 26 seconds fast (3) each year (2) by sun time. (1) Our calendar (4) will not be fast (3) by a whole day (2) for at least 3,000 years. |
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