About site: Astronomy/Calendars and Timekeeping - The Calendar, Leap Years and the Year 2000
Return to Science also Science
  About site: http://chemistry.csudh.edu/oliver/smt310-handouts/calendar.htm

Title: Astronomy/Calendars and Timekeeping - The Calendar, Leap Years and the Year 2000 An explanation of the calendar including the origin of the day, week, month and year.
Calendar_Studies Articles on the Gregorian and Julian calendars, the ISO date format, the Julian day number system, the Maya calendar, the Goddess lunar calendar, the Liberalia Triday Calendar and C functions for date

Calendars_through_the_Ages History and FAQs of calendars, from ancient Rome to outer space. Including Julian, Gregorian, Jewish, Islamic, Chinese, and Mayan.

Calendopaedia The Encyclopaedia of Calendars.

Calendrical_Calculations Published by Cambridge University Press. Gives a unified algorithmic presentation of the Gregorian, ISO, Julian, Coptic, Ethiopic, and Islamic civil calendars.

The_Chinese_Calendar The mathematics of the Chinese calendar. Explains the rules for the Chinese calendar.

The_Difference_Between_the_Millennium_and_Year_2000 Questions and answers to satisfy the hearts of true millennium buffs.


  Alexa statistic for http://chemistry.csudh.edu/oliver/smt310-handouts/calendar.htm





Get your Google PageRank






Please visit: http://chemistry.csudh.edu/oliver/smt310-handouts/calendar.htm


  Related sites for http://chemistry.csudh.edu/oliver/smt310-handouts/calendar.htm
    Greenwich_Time__Home_of_World_Time_(GMT)_since_1884 Complete guide to times in every time zone in the world.
    Hindu_Calendar_Dates_52nd_Century Explains the cosmological and astronomical influences in creating the Indian calendar.
    Indian_Moons A list of many American Indian tribe's names for months, days, and other calendar related information.
    The_Islamic_Calendar The mathematics of the Islamic calendar in Singapore.
    The_Julian_and_Gregorian_Calendars Explanations of the Julian Calendar, the Gregorian Reform, the adoption of the Gregorian Calendar, the length of the tropical year and related matters.
    Julian_Day_Numbers An explanation of the Julian day number system used by astronomers and calendricists.
    Leap_Seconds Civil time is occasionally adjusted by one second increments called leap seconds. A detailed explanation of what a second actually is, and why leap seconds are necessary.
    LunarCal_-_A_Perpetual_Chinese_Lunar_Calendar LunarCal is a 160-year perpetual Chinese Lunar Calendar for 1900 to 2060. Chinese festivals are listed and the moon phase is displayed.
    Lunisolar_Calendar Lunar calendar with lunations, from new moon to new moon, instead of months. Moon phase on each day. Chinese, Jewish, and Islamic months. Eclipses, meteors, planets, star charts. Christian, Pagan, Isl
    Maya_Calendar_2000 The calendar was the center of Maya life and their greatest cultural achievement. To carry out their astronomical calculations they developed a sophisticated mathematical system. The Maya Calendar web
    Millennium_Mistake Explains the difference between millenium and year 2000 as the absence of a year zero.
    Rosetta_Calendar An online handy tool for converting to and from the Gregorian, Julian and Jewish calendars.
    Time_and_Date Lots of time and date related information, such as yearly and monthly calendars, counters, countdown, and the world clock which shows the current time in cities all over the world.
    Time_and_Dates Information on date, time, and time zones from the New York Public Library.
    Types_of_Calendars An explanation of lunar, solar, lunisolar, rule-based and other types of calendars.
    World_Calendar/Clock,_Appointments,_Sun/Moon_positions,_Metric/Calendar_Conversion PlexGlobe is a productivity toolkit for global users and businesses that includes: - World clock and calendar such as Chinese and so on.
    World_Holidays__Weeks_and_Months Information on the origin of the week, and etymology of month and weekday names.
    ComSpec3D An online tool for calculation and visualisation of infrared and Raman spectroscopic results, with normal mode information.
    CytoSpec_Inc_ Software for the analysis of infrared spectral maps including chemical mapping, cluster mapping, PCA and ANN imaging. Includes glossary, downloads and contacts in Croton-on-Hudson, NY.
    Dr__Georgiou_Lab_of_Analytical_Chemistry Research into olive oil analysis, pesticides formulation analysis, flow injection, using analytical Raman spectroscopy and biosensors, at the Agricultural University of Athens, Greece.
    Infrared_identification_of_Organic_Unknowns Includes a brief description of the theory, a step-by-step guide to peak assignment and some problems.
    Infrared_Spectroscopy Includes information on the principles, absorption peaks for organic molecule functional groups and sample preparation methods, as part of the general program at Worcester Polytechnic Institute, Massa
    Infrared_Spectroscopy_and_Greenhouse_Gases Introduction and overview, maintained at the Department of Chemistry, Widener University, Chester, Pennsylvania.
    Infrared_Spectroscopy_of_Overtones_and_Combination_Bands [PDF] A paper on the analysis and mechanisms in these bands.
    IR_Spectroscopy_Tutorial Contains an introduction to infrared spectroscopy as well as sample infrared spectra.
    Micro-Raman_spectroscopy Overview of research applications in the field of art analysis and microbiological identification at laboratories Ghent University, based in Belgium.
    NIR_Publications Resources, including books, bimonthly newsletter, and Journal of Near Infrared Spectroscopy offered in electronic, CD-ROM and hardcopy. Includes abstracts and a search facility, with full text availab
    Infrared_and_Raman_Spectra_Interpretation_by_Group_Frequencies Five days of lectures in the field coupled with FT-IR laboratories and workshops at Stevenson Science Center, organized by the Fisk Inrared Institute in Nashville, TN. (May 12, 2003)
    All_Headline_News__Technology Continuously updated headline links from several news sources.
    Ananova_News__Technology Breaking tech news from around the world.
    BBC_News__Technology News and features about the latest technology advances including e-commerce, digital media and gaming. Offers selected video and audio programmes.
    Chicago_Tribune__Technology_Silicon_Prairie News and features, product reviews, blogs and columnist James Coates. Offers email newsletter. [requires free registration]
    CNET_News_com Computing and technology news service presents original stories and investigative reports in real-time.
    CNN_com__Technology Presents a top stories section with news about the internet, games, business tech and personal tech. Includes links to special reports.
    Economist_com__Technology_Quarterly In-depth coverage of tech news and issues with full archives. Includes breaking news and forum.
    Google_News__SciTech Science and technology news from Google's automatically edited web news filter.
    Guardian_Unlimited__Technology News and features about the internet and technology. Includes business solutions, science news, e-issues and special reports plus web watch, gadgets, games, blogs and Ask Jack.
    Into_Tomorrow_with_Dave_Graveline Radio show covers the latest in consumer electronics and technology for three hours every Sunday plus daily one-minute features. Listen live and to archived TechNews Hour shows. [RealAudio]
    MSNBC_News__Technology_&_Science Offers breaking news along with features about science, space, games and gadgets, tech tools, Tech Talk TV show and special reports.
    MSNBC_Technology_News The latest news on technology, including computer virus information and space news.
This is sites2007.com cache of m/ as retrieved on 2008.12.02 sites2007.com's cache is the snapshot that we took of the page as we crawled the web. The page may have changed since that time.
The Calendar, Leap Years and the Year 2000 ADThis page has been visited times since March 2, 1999 The Calendar, Leap Years and the Year 2000 ADThanks to the Science and Engineering Research Councilof the Royal Greenwich Observatory. This informationis reprinted from files found in the World Wide WebTHE CALENDARA calendar is a system of reckoning the time over extendedintervals by combining days into longer groupings which arelinked to the way in which we live. The groupings often havereligious significance and some of the groups are linked toastronomical periods. Our calendar is made up of days, weeks, months and years. Theday is the rotational period of the Earth; the week is a purelyartificial period linked to the Biblical story of creation; the monthis linked to the period of the Moon and the year is linked to theEarth's period of rotation around the Sun. Other CalendarsThe Jewish calendar and the Moslem calendar are intimatelyconnected with the Moon. The Jewish calendar is now a fixedcalendar with rather complex rules for its construction. Thelength of the Jewish year may be 353, 354 or 355 days or 383, 384or 385 days. Each month has 29 or 30 days. The Moslem calendar is also a fixed calendar, but the religiousfestivals depend on visual sightings of the New Moon. The lengthof the Moslem year is 12 months of alternate lengths 30 and 29days, except for the 12th month which can have either 29 or 30days. The calendar is kept in adjustment with the Moon using acycle of years of different length. The DayThe definition of the day seems very simple. It should be the timetaken for one passage of the Sun across the meridian to its nextcrossing. Unfortunately the Earth's movement around the Sun isnot circular and this causes the time indicated by a sundial to bedifferent from that measured by a clock. (The difference is calledthe Equation of Time and is describy a clock. (The difference is called the Equation of Time and is described in a separate pamphlet.) Nor is the Earth's rotation period constant, although the variationsare very small. So we use a length for the day which representsthe Earth's average rotation period. Occasionally we have toinsert `leap-seconds' to correct from this exact measure to theslightly irregular rotation of the Earth. The WeekMosaic law forbidding work on every seventh day established aseven-day period as a measure of Jewish time. This passed overinto the Christian church and gradually became established in theRoman calendar. The astrological practice of naming the daysusing the names of the Sun, Moon and the five known planets alsoyielded a seven day period. The names that we give to the days of the week are still based onthis nomenclature. In English Sunday and Monday are namedafter the Sun and Moon while the other days of the week arenamed after the teutonic versions of the gods that correspond toeach planet. Tiu = Mars, Woden = Mercury, Thor = Jupiter andFreya = Venus, Saturday keeping its latin connection with Saturn. The MonthMany ancient calendars were based on the lunar cycle. The lunarmonth is 29.530589 days and the number of lunations in a year is12.368267. The most common scheme was to have 12 montommon scheme was to have 12 months of30 days with either arbitrary or calculated additional days ormonths to bring the system into accord with the solar year. Originally the Roman calendar had 10 months Martius (namedafter Mars and indicating the time for resumption of war), Aprilis(after the word for `to open', hence Spring), Maius (after Maia, thegoddess of growth), Junius (after juvenis, meaning youth),Quintilius, Sextilis, Septembris, Octobris and Decembris (meaningthe fifth to tenth months). The Romans had a dislike of evennumbers as these symbolized death and so the months had either29 or 31 days. King Numa increased the number of months to 12by introducing Januarius (after the god Janus, the protector ofdoorways and hence the opening of the year) and Februarius (afterFebrualia, the time for sacrifices at the end of the year). The orderof the months was later changed. In order to reconcile the solar and lunar years,at therecommendation of Sosigenes Julius Caesar altered the lengths ofthe months and the change to our present format was completedby Caesar Augustus. They both claimed the names of one of themonths and this gave rise to Julius and Augustus which replacedQuintilius and Sextilis. The YearThe number of days in one revolution of the Earth around the Sunis f the Earth around the Sun is 365.2422 days. Unfortunately, this is not a whole number andso if we wish to keep the calendar in track with the seasons wemust adopt some form of variable year length. The first major attempt to accomplish this was by Julius Caesar. Besides pinching a day from the last month of the year (thenFebruary) to make `his' month, July, have 31 days he introducedthe Julian calendar. February was further despoiled by AugustusCaesar who also purloined a day so as to make `his' month,August, also have 31 days. As some sort of compensation theleap-day was given to February. The Julian calendar introduced a year of length 365 days with aleap-year every 4 years. It also moved the start of the year fromMarch 25 to January 1, supposedly the longest day. The adoptedlength of the year, 365. 25 days, is only slightly different from theactual length, 365. 2422 days, but over the centuries thedifference mounts up and by the 16th century had becomenoticeable. The effect is to move Spring and the date of Easter,which is related to the vernal equinox, closer to the date ofChristmas. The Gregorian reform to the calendar altered the rule fordetermining if a year should be a leap-year by stating thatcentenary years should only be leap-years if they were divisible by400. It also dropped several days from the caled several days from the calendar so that thevernal equinox was brought back to March 21. The mean lengthof the calendar year is now 365. 2425 days and the errorcompared with the true value amounts to only 3 days in 10,000years. LEAP YEARSThe year is defined as being the interval between two successivepassages of the Sun through the vernal equinox. Of course, whatis really occurring is that the Earth is going around the Sun but itis easier to understand what is happening by considering theapparent motion of the Sun in the sky.The vernal equinox is the instant when the Sun is above theEarth's equator while going from the south to the north. It is thetime which astronomers take as the definition of the beginning ofSpring.The year as defined above is called the trove is called the tropical year and itis the year length that defines the repetition of the seasons. Thelength of the tropical year is 365.24219 days.In 46 BC Julius Caesar established the Julian calendar which wasused in the west until 1582. In the Julian calendar each yearcontained 12 months and there were an average of 365.25 days ina year. This was achieved by having three years containing 365days and one year containing 366 days. (In fact the leap yearswere not correctly inserted until 8 AD).The discrepancy between the actual length of the year, 365.24219days, and the adopted length, 365.25 days, may not seemimportant but over hundreds of years the difference becomesobvious. The reason for this is that the seasons, which depend onthe date in the tropical year, were getting progressively out ofkilter with the calendar date. Pope Gregory XIII, in 1582,instituted the Gregorian calendar, which has been used since then.The change from the Julian calendar to the Gregorian involved thechange of the simple rule for leap-years to the more complex onein which century years should only be leap-years if they weredivisible by 400. For example, 1700,1800 and 1900 are notleap-years whereas 2000 will be.The net effect is to make the adopted average length of the year365.2425 days. The dhe year 365.2425 days. The difference between this and the true lengthwill not have a serious effect for many thousands of years. (Theerror amounts to about 3 days in 10,000 years.)The adoption of the Gregorian calendar was made in Catholiccountries in 1582 with the elimination of 10 days, October the 4thbeing followed by October 15th. The Gregorian calendar alsostipulated that the year should start on January 1. In non-Catholiccountries the change was made later; Britain and her coloniesmade the change in 1752 when September 2nd was followed bySeptember 14 and New Year's Day was changed from March 25to January 1.MillenniaA millennium is a period of 1000 years. The question of whichyear is the first year of the millennium hinges on the date of thefirst year AD.Unfortunately the sequence of years going from BC to AD doesnot include a Year 0. The sequence of years runs 3 BC, 2 BC, 1BC, 1 AD, 2 AD, 3 AD etc. This means that the first year of thefirst millennium was 1 AD. The one thousandth year was 1000AD and the first day of the second millennium was 1001 AD.It is thus clear that the start of the new millennium will be 1 Jan2001.Celebrations.The year 200="br1"> The year 2000 AD will certainly be celebrated, as is natural for ayear with such a round number but, accurately speaking, we willbe celebrating the 2000th year or the last year of the millennium,not the start of the new millennium. Whether this will be anexcuse for more celebrations in the following year will have to beseen!/html>
 

An

explanation

of

the

calendar

including

the

origin

of

the

day,

week,

month

and

year.

http://chemistry.csudh.edu/oliver/smt310-handouts/calendar.htm

The Calendar, Leap Years and the Year 2000 2008 December

dvd rental

dvd


An explanation of the calendar including the origin of the day, week, month and year.

Rules




© 2005 Internet Explorer 5+ or Netscape 6+

Recommended Sites: 1. Arts - Business - Computers - Games - Health - Home - Kids and Teens - News - Recreation - Reference - Regional - Science - Shopping - Society - Sports - World Miss Gallery - Top Anime Hentai - DVD rental by mail - Credit Cards - Balance Transfer Credit Cards - Online Loans - Credit Report - Nature's Sunshine
2008-12-02 11:15:21

Copyright 2005, 2006 by Webmaster
Websites is cool :)