Calendar

1. Calendar what...for why don't what when how long where which how old who why how come how far how + adj/adv whose how much how many how

2. Calendar • Why do we use calendars? • Celebrate holidays – commandment from G_od • To get ready for the coming seasons • Helps to make plans • More… http://en.wikipedia.org/wiki/Hebrew_calendar

3. When is Rosh Hashanah evening? • The 29th of Elul

4. Convert your birth date to the Jewish calendar 1st of Tishrei, 5772 = Thu, 29 September 2011 • http://www.hebcal.com/converter

5. Moon’s Phase - US Navy Web Site! http://tycho.usno.navy.mil/vphase.html

6. Hebrew Calendar • Combination of Solar calendar and Lunar calendar • The Jewish year is based on the earth movement around the sun • The Jewish month is based on the moon movement around the earth

7. אשָׁמוֹר, אֶת-חֹדֶשׁ הָאָבִיב, וְעָשִׂיתָ פֶּסַח, לַיהוָה אֱלֹהֶיךָ:  כִּי בְּחֹדֶשׁ הָאָבִיב, הוֹצִיאֲךָ יְהוָה אֱלֹהֶיךָ מִמִּצְרַיִם--לָיְלָה. 1 Observe the month of Abib (the spring D.N.), and keep the passover unto the LORD thy God; for in the month of Abib the LORD thy God brought thee forth out of Egypt by night. But Why?Why do we use the combination of Lunar and Solar Calendars (or the Lunisolar Calendar)? Step one Only the Solar Calendar will allow for us keep G_od’s commandment to have Passover during the spring. Deuteronomy Chapter 16דְּבָרִים http://www.mechon-mamre.org/p/pt/pt0516.htm

8. א  וַיֹּאמֶר יְהוָה אֶל-מֹשֶׁה וְאֶל-אַהֲרֹן, בְּאֶרֶץ מִצְרַיִם לֵאמֹר. ב  הַחֹדֶשׁ הַזֶּה לָכֶם, רֹאשׁ חֳדָשִׁים:  רִאשׁוֹן הוּא לָכֶם, לְחָדְשֵׁי הַשָּׁנָה. 1 And the LORD spoke unto Moses and Aaron in the land of Egypt, saying: 2 This month shall be unto you the beginning of months; it shall be the first month of the year to you. STEP TWOThe months depend on the cycle of the moon. Our sages understood it from the word “This” in the flowing quote:Exodus Chapter 12 שְׁמוֹת http://tora.us.fm/tnk1/tora/jmot/jm-12-02.html

9. Time and place are two fundamental coordinates of life, and, in particular, of Jewish life and teaching. As regards "place," the Torah focuses on the Holy Land, the site of the Temple and the sacred City of Jerusalem, as the spiritual center for the Jewish people. One can also think of the Jewish home and of the synagogue as examples of places where there is something special, a quality of holiness. • In the account of the Exodus there is another fundamental idea: the sanctification of time. This is expressed in the Divine instruction to Moses and the Jewish people that "This month shall be for you the first of the months, it will be the first month of the year." The Sages understand this as the law to sanctify the New Moon every month, and to calculate the details of the Jewish calendar. • A key element in celebrating Passover and indeed any Jewish festival is the concept of the Jewish calendar. This runs as a lunar calendar, in which the months follow the phases of the moon. But the Jewish calendar also has to take into account the solar year, in order that Passover, in the first month, will always fall in the spring. Hence in a leap year, an extra month is added to the Jewish year. • In ancient times witnesses who had seen the New Moon would come to the Law Court in Jerusalem, and there the Sages would proclaim the start of the new month. In later generations this became difficult on account of Roman persecution. The sage Hillel II (4th century CE) therefore calculated the details of the Jewish calendar and today the entire Jewish people around the world follow his system. • The command to sanctify the New Moon and calculate the Jewish calendar was the first command given to the Jewish people as a whole. Rashi even suggests that this command might have been the beginning of the entire Torah. • Through the calendar the Jewish people sanctify and transform time. Shabbat comes automatically every seven days; but the Jewish calendar, put in the hands of the leaders of the Jewish people, determines which day is the New Moon, and therefore which days are Festivals. http://www.chabad.org/parshah/article_cdo/aid/823789/jewish/Sanctifying-Time.htm

10. http://www.daat.ac.il/daat/shabat/luach/month3.html

11. Problem ! • For the moon to go around the earth it takes 29.5 days • 12 months in a year • 12*29.5=354 days in a lunar year • The Solar year has 365 days! • 365-354=11 • Eleven days are “missing” • How is this problem solved?

12. Solution ! • Add a lunar month every 2-3 years in the Jewish Calendar • This year is called: Shana Meuberth = leap year • Every 19 years there are 7 leap years • Let’s do some math….

13. Jewish year Given: 29.5 days a month 12 month a year 7 times add a month in 19 years 29.5*12*19=6726 29.5*7= 206.5 Total 6932.5 days in 19 years Solar year Given: 365 days in a solar year 365*19=6935 Total 6935 days in 19 years How many days are in19 years? Not 100% solution but not so bad

14. Types of Years • A year in the Hebrew calendar is normally twelve months: Tishrei, Cheshvan, Kislev, Tevet, Sh'vat, Adar, Nisan, Iyar, Sivan, Tammuz, Av, and Elul. An extra month (Adar is replaced with Adar I and Adar II) is intercalated in seven of every nineteen years (years 3, 6, 8, 11, 14, 17, and 19). Every 19-year cycle thus contains 235 months. These two cycles of years and months are so close that they diverge at the rate of only 4.5 days every 1000 years. • Because a lunar month is not a whole number of days, the length of the months can be either 29 or 30 days. A typical year alternates 30- and 29-day months, beginning with Tishrei, which is 30 days. In leap years, Adar I is 30 days and Adar II is 29 days. To further bring the calendar into alignment with the lunar cycle, a year may need to be shortened or lengthened by one day: Kislev may be shortened to 29 days, or Cheshvan may be lengthened to 30 days. Thus, there are six types of years: • Defective common years, with 353 days • Regular common years, with 354 days • Excessive common years, with 355 days • Defective leap years, with 383 days • Regular leap years, with 384 days • Excessive leap years, with 385 days http://www.shirhadash.org/calendar/abouthcal.htm l

15. Time and place are two fundamental coordinates of life, and, in particular, of Jewish life and teaching. As regards "place," the Torah focuses on the Holy Land, the site of the Temple and the sacred City of Jerusalem, as the spiritual center for the Jewish people and the world. One can also think of the Jewish home and of the synagogue as examples of places where there is something special, a quality of holiness. • In the account of the Exodus there is another fundamental idea: the sanctification of time. This is expressed in the Divine instruction to Moses and the Jewish people that "This month shall be for you the first of the months, it will be the first month of the year." The Sages understand this as the law to sanctify the New Moon every month, and to calculate the details of the Jewish calendar. • A key element in celebrating Passover and indeed any Jewish festival is the concept of the Jewish calendar. This runs as a lunar calendar, in which the months follow the phases of the moon. But the Jewish calendar also has to take into account the solar year, in order that Passover, in the first month, will always fall in the spring. Hence in a leap year, an extra month is added to the Jewish year. • In ancient times witnesses who had seen the New Moon would come to the Law Court in Jerusalem, and there the Sages would proclaim the start of the new month. In later generations this became difficult on account of Roman persecution. The sage Hillel II (4th century CE) therefore calculated the details of the Jewish calendar and today the entire Jewish people around the world follow his system. • The command to sanctify the New Moon and calculate the Jewish calendar was the first command given to the Jewish people as a whole. Rashi even suggests that this command might have been the beginning of the entire Torah. • Through the calendar the Jewish people sanctify and transform time. Shabbat comes automatically every seven days; but the Jewish calendar, put in the hands of the leaders of the Jewish people, determines which day is the New Moon, and therefore which days are Festivals. http://www.chabad.org/parshah/article_cdo/aid/823789/jewish/Sanctifying-Time.htm

16. ראש השנה דף כה עמוד אמסכת http://daf-yomi.com/Dafyomi_Page.aspx?vt=1&massechet=291&amud=49&fs=0 http://he.wikisource.org/wiki/%D7%A8%D7%90%D7%A9_%D7%94%D7%A9%D7%A0%D7%94_%D7%9B%D7%94_%D7%90

17. אמר להם ר"ג ]רבן גמליאל] כך מקובלני מבית אבי אבא אין חדושה של לבנה פחותה מעשרים ותשעה יום ומחצה ושני שלישי שעה וע"ג חלקים Synodic Month = New moon to new moon

18. Helek • The helek (Hebrewחלק, meaning "portion", plural halakimחלקים) is a unit of time used in the calculation of the Hebrew calendar. The hour is divided into 1080 halakim. A helek is 31/3 seconds or 1/18 minute. http://en.wikipedia.org/wiki/Helek

19. אין חדושה של לבנה פחותה מעשרים ותשעה יום ומחצה ושני שלישי שעה וע"ג חלקים • 29 ימים • חצי יום • 2/3 שעה • 73 חלקים • 29 ימים • חצי יום • 2/3 שעה • 73 חלקים + + + Not/less than/from

20. The average length of the synodic* month is: • Gmarah: 29.530594 days • NASA: 29.530589 days • From Britannica: 29.530588 days • Error: 1 day after about 16 millennia *Synodic Month = New moon to new moon • http://en.wikipedia.org/wiki/Lunar_month • http://eclipse.gsfc.nasa.gov/SEsaros/SEsaros.html • http://www.britannica.com/EBchecked/topic/578490/synodic-month

22. http://chem.ch.huji.ac.il/nmr/foo/ppt/nmoon_files/frame.htm In my computer

23. Lunisolar calendar • The Hebrew, Buddhist, Hellenic, Hindu lunisolar, Burmese, Tibetan, Chinese, Vietnamese, Mongolian, and Korean calendars are all lunisolar. http://en.wikipedia.org/wiki/Lunisolar_calendar