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| Oh remember how short my time is:
For what vanity hast thou created all the children of men! Ps 89:47 |
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TIME fact 2:TIME: part 2
of 9
Time - for convenience - is divided into different groupings.
A day = 24 hours, this is called a nychthemeron
7 days = 1 week or a sennight
14 days = 2 weeks or a fortnight
One of the most significant divisions is the Calendar Year
The exact length of a calendar year is equal to 365 days, 5 hours, 48 minutes, 46 seconds.
A year is the time period between two successive crossings of the celestial equator by the
sun at the vernal equinox.
Because the length of a year is not a whole number it has affected the development of the
calendar over the years. Over a long period of time the odd length of a year will
accumulate and cause quite an error. The current calendar used by much of the world is the
Gregorian calendar. It was named for Pope Gregory XII of the 16th century. The Gregorian
calendar attempts to compensate for the accumulated errors of the year by adding an extra
day to February every 4 years.
Mankind has developed many other calendars besides the Gregorian calendar. Most of these
calendar are lunar months, some are solar calendars, others are a combination of the two.
Two are listed here today - others will be listed tomorrow.
Babylonian calendar - A lunar calendar. This calendar was composed of alternating months
of 29 and 30 days. These months roughly equaled a year of 354 lunar days. As time passed
the calendar became noticeably misaligned
with astronomical events. An extra month was
then added to the year. Every 8 years, three extra months were added to the year to
coordinate the calendar with the solar year.
Chinese Calendar - A lunar calendar. A calendar of 12 periods having either 29 or 30 days
to compensate for the cycle of moon phases that equals 29.5 days. The new year begins on
the first new moon over China after the sun enters Aquarius (between 1/21 and 2/19).The
Chinese new year is therefore three to seven weeks into the start of the Gregorian New
year. The year is given both a number and a name. The year 1998 is the year of the Tiger,
this is year 4635 of the Chinese era. The calendar is synchronized with the solar year by
the addition of extra months at fixed intervals.
Sources: The Handy Science Answer Book - Visible Ink |
