Cancer is the 4th astrological sign in the Zodiac, originating from the constellation of Cancer. It spans the 90° to 120° of the zodiac, between 90° and 120° of celestial longitude. Under the tropical zodiac, the Sun transits this area on average between June 21 and July 22. Each astrological sign tends to have at least one key characteristic that really identifies it. Cancers, whether fairly or unfairly, are known for their moodiness. This is because Cancer’s ruler, the Moon, waxes and wanes with the changing tides.