Constellations have been used to tell time for hundreds of years. The 12 zodiacal constellations are used to symbolize the 12 months in a yearly cycle. Zodiac, meaning "circle of little animals" in the Greek form, marks the path that the Sun takes and, it is believed in some cultures that, depending upon which month you were born in, this would determine your personality traits and character. This is because with the association of each month, the animal that symbolizes the month in which you were born would carry some of their likenesses to your birth.
Constellations were read and divided into 12 different cycles. This is, in part, how the modern day calendar developed. Each cycle, having bee equal in longitude, shows the constellations in certain places throughout the year. This study of the constellations also signifies our discovery and assignments to the yearly seasons.
It is difficult to be in a city and see the constellations in the sky... This is due to what astrologers have dubbed "light pollution". There are too many sources of light, street lamps, traffic lights, etc, that contribute to filling the night sky with light from earth. Therefore, we are unable to see past those lights into the darkness. This blocks our full few of the stars in the sky. In the country, or more rural areas, we are able to look at the stars from an unobstructed view. This allows the viewing of the many constellations in the night sky.
From Andromeda to Vulpecula, that 88 known constellations are divided by month. What's strange is, and this would be a good question to research, is that the zodiacal sign assigned to a certain month doesn't show up as a constellation that takes place in that month. For example, if you are a Gemini by definition of zodiacal signs, the constellation of Gemini doesn't appear in June, it appears in February. Libra's constellation actually appears in June. Why this is would be worthwhile in researching.
The stars themselves that make up the constellations are named. Beginning at acamar and ending with zuben elschemali, as we know it now, one could imagine that new stars were forming every year. This is not the case. Stars do not burn out and stars do not fall from the sky. When there is a "shooting star", this is really a piece of an asteroid full of iron that breaks off due to an explosion in orbit. Friction caused by this hunk coming into the earth's atmosphere is actually the glow that we see, not the shining of a star. Sounds like some Star Trekky thing, right? Creators were not too far off when they developed these shows, it's just that at that time, not many knew it.