month

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Related to January: Capricorn

month

month, in chronology, the conventional period of a lunation, i.e., passage of the moon through all its phases. It is usually computed at approximately 29 or 30 days. For the computation of the month and its harmony with the solar calendar and for the months in others than the Gregorian calendar, see calendar. For the difference between the sidereal month and the synodic month, see moon. Certain stones have in ancient and modern times been connected with the months; these lucky stones, or birthstones, are often given as follows: January [from the god Janus]: garnet; February [Lat.,=expiatory, because of ancient rites]: amethyst; March [from the god Mars]: bloodstone or aquamarine; April: diamond; May: agate or emerald; June [from the gens Junius]: pearl or moonstone; July [from Julius Caesar]: ruby or onyx; August [from Augustus]: carnelian or peridot; September [Lat.,= seven; formerly the 7th month]: chrysolite or sapphire; October [eight]: beryl, tourmaline or opal; November [nine]: topaz; December [ten]: turquoise or zircon.
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Month

month

The period of the Moon's revolution around the Earth with reference to some specified point in the sky (see table). The differences in the monthly periods result from the complicated motion of the moon.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Month

 

an interval of time nearly equal to the period of revolution of the moon about the earth. Different types of months are distinguished (see Table 1 and Figure 1). These include (1) the synodic month, which is the period of the sequence of the lunar phases (it serves as the basis for lunar calendars);

Table 1. Length of various types of months
Type of monthMean solar daysMean solar time
Synodic .....29.53058829 days12 hr44 min3 sec
Sidereal .....27.32166127 days7 hr43 min12 sec
Tropical .....27.32158227 days7 hr43 min4 sec
Anomalistic .....27.55455027 days13 hr18 min33 sec
Nodical .....27.21222027 days5 hr5 min36 sec

(2) the sidereal month, during which the moon performs a complete revolution about the earth and returns to its original position relative to the stars; (3) the tropical month, which is the period during which the moon returns to a given longitude; (4) the anomalistic month, which is the interval of time between successive passages of the moon through the perigee; and (5) the nodical month, which is the period of time between successive passages of the moon through the same node of its orbit (this concept is important for the theory of eclipses). In the Gregorian calendar, the year is divided into 12 months, each month containing from 28 to 31 days; this calendar does not agree with the lunar phases.

Figure 1. Difference between synodic and sidereal months. (1) and (3) are the relative posiositions of the sun, earth, and moon at which a full moonon occurs (a time interval of oneone synodic month); (2) is the position of the moon after a complete revolution about the earth (a time interval of one siderealreal month).

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

month

[mənth]
(astronomy)
The period of the revolution of the moon around the earth (sidereal month).
The period of the phases of the moon (synodic month).
The month of the calendar (calendar month).
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

month

1. one of the twelve divisions (calendar months) of the calendar year
2. the period of time (tropical month) taken by the moon to return to the same longitude after one complete revolution around the earth; 27.321 58 days (approximately 27 days, 7 hours, 43 minutes, 4.5 seconds)
3. the period of time (sidereal month) taken by the moon to make one complete revolution around the earth, measured between two successive conjunctions with a distant star; 27.321 66 days (approximately 27 days, 7 hours, 43 minutes, 11 seconds)
4. the period of time (lunar or synodic month) taken by the moon to make one complete revolution around the earth, measured between two successive new moons; 29.530 59 days (approximately 29 days, 12 hours, 44 minutes, 3 seconds)
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in classic literature ?
On the 12th of January, 1893, I was seventeen, and the 20th of January I signed before the shipping commissioner the articles of the Sophie Sutherland, a three topmast sealing schooner bound on a voyage to the coast of Japan.
On 2nd January we had made 11,340 miles, or 5,250 French leagues, since our starting-point in the Japan Seas.
Two days after crossing the coral sea, 4th January, we sighted the Papuan coasts.
So the countess remained in the country, and the count, taking Sonya and Natasha with him, went to Moscow at the end of January.
There are secrets in all families, you know)The case is, that a party of friends are invited to pay a visit at Enscombe in January; and that Frank's coming depends upon their being put off.
What put the "whole population of Paris in commotion," as Jehan de Troyes expresses it, on the sixth of January, was the double solemnity, united from time immemorial, of the Epiphany and the Feast of Fools.
It must be stated, in honor of the good sense of the loungers of Paris, that the greater part of this crowd directed their steps towards the bonfire, which was quite in season, or towards the mystery play, which was to be presented in the grand hall of the Palais de Justice (the courts of law), which was well roofed and walled; and that the curious left the poor, scantily flowered maypole to shiver all alone beneath the sky of January, in the cemetery of the Chapel of Braque.
Their departure took place in the first week in January. The Middletons were to follow in about a week.
"And that vacation begins on the first of January and ends on the thirty-first of December?"
It was cold in the room of the bell tower of the church on that January night and almost as soon as he came into the room Curtis Hartman knew that if he stayed he would be ill.
January 29th, being at anchor under Cape Gregory: a very hard gale from W.
I turned this truism over in my mind as, in the frosty dawn of a January morning, I hurried down the steep and now icy street which descended from Mrs.