Editing New moon (section)

== Lunisolar calendars ==
{{See also|Lunisolar calendar}}

===Hebrew calendar===
The new moon, in Hebrew [[Rosh Chodesh]], signifies the start of every Hebrew month and is considered an important date and minor holiday in the [[Hebrew calendar]]. The modern form of the calendar practiced in Judaism is a rule-based [[lunisolar calendar]], akin to the [[Chinese calendar]], measuring months defined in lunar cycles as well as years measured in solar cycles, and distinct from the purely lunar [[Islamic calendar]] and the predominantly solar [[Gregorian calendar]]. The Jewish months are fixed to the annual seasons by setting the new moon of [[Aviv]], the ''barley ripening'', or ''spring'', as the first moon and head of the year.<ref>{{Bibleverse|Exodus|12:1-2|HE}}</ref>  Since the [[Babylonian captivity]], this month is called [[Nisan]], and it is calculated based on mathematical rules designed to ensure that festivals are observed in their traditional season. Passover always falls in the springtime.<ref>{{Cite web |last=Posner |first=Menachem |year=2016 |title=How Does the Spring Equinox Relate to the Timing of Passover? |url=http://www.chabad.org/holidays/passover/pesach_cdo/aid/495531/jewish/How-Does-the-Spring-Equinox-Relate-to-the-Timing-of-Passover.htm |access-date=9 December 2016 |website=Chabad}}</ref> This fixed lunisolar calendar follows rules introduced by [[Hillel II]] and refined until the ninth century.  This calculation makes use of a mean lunation length used by [[Ptolemy]] and [[Lunar theory#Babylon|handed down from Babylonians]], which is still very accurate: ca. 29.530594 days vs. a present value (see [[#Determining new moons: an approximate formula|below]]) of 29.530589 days.  This difference of only 0.000005, or five millionths of a day, adds up to about only four hours since Babylonian times.{{citation needed|date=May 2015}}

===Chinese calendar===

The new moon is the beginning of the month in the [[Chinese calendar]]. Some Buddhist Chinese keep a vegetarian diet on the new moon and full moon each month.<ref>{{Cite web |title=A Buddhist Perspective on Fasting |url=http://www.urbandharma.org/udharma9/fasting.html |access-date=2016-09-18 |website=urbandharma.org}}</ref>

=== Hindu calendar ===
[[File: Amavasya and Prathama tithi.jpg|thumb|Amavasya and Prathama tithi]]
The new moon is significant in the lunar [[Hindu calendar]]. The first day of the calendar starts the day after the dark moon phase ([[Amavasya]]).<ref>{{cite book |last1=Long |first1=Jeffery D. |title=Historical Dictionary of Hinduism |date=9 September 2011 |publisher=Scarecrow Press |isbn=978-0-8108-7960-7 |pages=76–77 |url=https://books.google.com/books?id=ZkkFCwAAQBAJ |language=en}}</ref><!-- next sentence suspended pending citation: 
, which is considered a powerful force for good or evil. The Hindu epic [[Mahabharatha]] states that the [[Kurukshetra War]] started this day, which was also a Tuesday (Mangalvaar, day of the week named after Mars). {{citation needed|date=May 2015}}  -->

There are fifteen moon dates for each of the waxing and waning periods. These fifteen dates are divided evenly into five categories: Nanda, Bhadra', Jaya, Rikta, and Purna, which are cycled through in that order.<ref name="Wilhelm">{{cite book |last1=Wilhelm |first1=Ernst |title=Classical Muhurta |date=2003 |publisher=Kala Occult Publishers |isbn=978-0-9709636-2-8 |pages=23–25 |url=https://books.google.com/books?id=3zMPFJy6YygC |access-date=4 June 2022 |language=en}}</ref>
Nanda dates are considered to be favorable for auspicious works; Bhadra dates for works related to community, social, family, and friends; and Jaya dates for dealing with conflict. Rikta dates are considered beneficial only for works related to cruelty. Purna dates are considered to be favorable for all work.<ref name="Wilhelm"/>{{rp|25}}

=== [[Babylonian calendar]] ===
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