01  Jan van de Velde's etching, The Twelve Months, (October) , published 1616, 18 x 28cms.

02 The Twelve Animals used in Chinese Divination of Fortune

03 The Twelve Gates of the Holy City of Jersusalem
from Holbein's illustrations to the Old Testament.

04 The Twelve Apostles.

The Twelve Tribes of Israel.

The Twelve Signs (Constellations) of the Zodiac.
 

Aries the Ram (21st March);
Taurus the Bull (20th April);
Gemini the twins (21st May);
Cancer the Crab (21st June) ;
Leo the Lion (23rd July) ;
Virgo the Virgin (23rd August);
Libra the Balance (23rd September);
Scorpio the Scorpion (23rd October);
Sagittarius the Archer (22nd November);
Capricorn the Goat (22nd December);
Aquarius the Watercarrier (20th January);
Pisces the Fishes (14th February).

The Twelve Good Friends of Man, maxims for the Salvation of the Soul in Russian Folklore, ie Toil, Obedience, Love and Truth.

The Twelve Months of the Year. (Derivations and the Labours of the month as represented in Les Très Riches Heures du Duc de Berry .
 
Janus , doorkeeper of heaven(the Duke's household at dinner).
Februalaia , the Roman custom of burning expiatory sacrifices( a snow covered landscape with livestock under cover and servants in front of a fire).
Mars , the God of War; the first month in antiquity - peasants plough the fields before the castle). According to Ovid, Mars was chosen because he was father of the Romans first prince, and thus was a harbinger of spring.
Aprilis , from Aperire, to open (young girls pick flowers, lovers exchange vows).
Maia , the name of the earth during the daedal season(the Duke and court in procession to celebrate the feast on May 1st).
Juno (most probably) celebrated at a festival at the beginning of this month (haymaking in the fields outside Paris).
Julius Caesar, who radically reformed the calendar.
Augustus, after the Emperor. July (corncutting and sheepshearing) and August (harvesting in the fields while the Duke rides out to hunt) were originally called Quintilis and Sextilis by the Romans.
September (peasants picking grapes for wine, the castle of Saumur) ,
October (sowing seeds and raking) ,
November and
December ( a boar hunt in the forest) constitute the seventh, eighth, ninth and tenth months.

The Beaufort Scale as used at Sea: 12 observable conditions
0 = calm
 
Light Air;
Light Breeze;
Gentle Breeze;
Moderate Breeze;
Fresh Breeze;
Strong Breeze;
Near Gale;
Gale;
Strong Gale;
Storm;
Violent Storm;
Hurricane.

See Dick File, Weather Facts , Oxford, 1991.