Aquarius means water carriers
March includes the signs Pisces and Aries.
One possible meaning is that 12 equals "S" sides of the zodiac, referring to the 12 signs in the zodiac. Another interpretation could be that 12 represents the 12 symbols or constellations in the zodiac system.
Capricorn
Taurus
the fox :D
Cancer~ xD
Capricorn
There are an endless supply of 'signs' so the question is not specific enough to answer.
12 Signs of the Zodiac
Pisces
cancer and sagittarius
Aries (Tropical Zodiac)