Astrology in my settings

So each age the names of the constellations and stars change

1st age Dawn AgeStars were in constant flux and people communicated with stars and saw the gods take to the heavens. Lots of sorcerers are born under a full moon they say. As gods came and went or retired or were forgotten the sky changed. Some stars were brighter but as their god became distant so did their star.

2nd age Night Age1 Great Eye - used to gaze down at the world killing what displeased it with rays
2 Dragon - the great mother dragon one of the progenitors of all life, Queen Tiamat
3 Twin Rods - rods used by a foreman or ruler or judge, also a measure 
4 Spider - formerly was the insect, great spider queen who's webs linked the continents 
5 Giant - giant king had seized heavens from gods, fathers of many races
6 The Skull - all power came from death and the great void of entropy
7 Whip - formerly was the worm, symbol of power, domination and slavery
8 Scorpion - viscous poisonous scorpion men helped to fight the gods
9 Bat - formerly was pterodactyl or lizard bird, who took the tablet of destiny from the gods
10 Kraken - great devourer from the sea and the stars who ruled stone cities of black magic
11 Hydra - great primordial beast of the waters, lord of serpentine power
12 Wheel of pain - subjugation, torture and humiliation of the weak was the great art then

3rd Age Stone Age
1 Eye - the great spirit eye in the sky watches all
2 Dragon - great mother dragon
3 Twin Spears - weapon of heroes
4 Crayfish - great sea monster
5 Lion - king of beasts, some are sabretooth
6 Tree - great tree supports universe
7 Cup - to carry and measure and share
8 Scorpion - viscous enemy of life
9 Eagle - great lord of sky
10 Turtle - great lord of the sea
11 Hydra - eternal serpent father
12 Wheel - great disc of the world, used as calendar, sundial and compass

4th age The age of Exilon1 Shepherd - protector of the flocks
2 Winged bull - bull of heaven
3 Twin Swords - heroes with swords often fighting monsters or beasts
4 Crab - terrible sea beast
5 Sphynx - great and terrible wise guardians of the gods
6 Barley Stalk - head of grain and art of agriculture
7 Balance - scales which measure wealth and virtue vs sin in afterlife
8 Scorpion - enemy of man
9 Anzu Bird - terrible god bird demon that battled the gods
10 Goat Fish - great sea goat brings water and fish
11 Hydra - ancient serpent of underworld, healer and prophet 
12 Chariot - vehicle of kings and the divine, messenger of gods
5th age The age of Humans1 Mirror - self reflection and vanity
2 Bull - stubborn and aggressive bull
3 Two Arrows - certainty and direction
4 Barrel - carries and protects
5 Lion - king of beasts
6 Maiden - fertility and the virgin goddess
7 Balance - measure and judgement and fairness
8 Scorpion - enemy of man
9 Hawk - lord of the sky
10 Dolphin - prince of the sea
11 Snake - biting tail in circle or figure 8 or two headed, space and time 
12 Wagon - great vehicle, symbol of trade and wealth

Each year has a name as well but after 1200 years these lists are broken.
Modern years date to the start of the age previously people refereed to years by names and kings but frequently were inconsistent and contrary.

There are still lots of variants. Monsters and abhumans often use the 2nd age reckoning still. In the second age as some races in the great monster alliance changes they changed the constellations. Much of the world was dark and frozen deserts but many beings made false suns to propagate thick alien jungles and crops some were different coloured. Some places had vast fungus forests. Underland and the surface were more alike.

The third age was mostly illiterate and the wizards and necromancers who grew in this time and ended it used the second age system which common folk couldn't comprehend so a popular version emerged. This third age form was used by shamen and megalith builders for a aeon.

The fourth age was a glorious age where long lost gods returned to rule the world and cities and writing and metal all returned. Complex taxonomies and lists were commonplace and astrology was frequently mentioned and incorporated into all kinds of fields. Every king had astrologers and listened to their daily advice on what colour to wear or food not to eat to avoid being usurped on Thursday. The cataclysm ended that age and faith in gods and supernatural experts changed. Art and religion became simpler and less boroque and no longer tried explaining all. 

The later 5th age is a age of materialism, exploration and sea empires. 5th age astrologers trying to sound more objective and methodical and shun the older systems. Wizards claim to be the greatest power of this age but gunpowder is probably second. The third great form of the empire is in civil way and has lost it's grip. Traders and merchants and slavers and vice peddlers and pirates cross the world now.

So various cultures used these in artworks and dungeon designs some on a huge scale with earthworks and gardens. Some with strange tests and magical ordeals. As you move on circle calendar and return from the start the tests become otherworldly and the flow of time alters for those taking the test. The most modern version is 12 wagons linked in a circle each is a dungeon room. Every time you make a circle level gets worse. Palaces often have rooms themed and named after these and some say palaces of the gods have these too.

Astrologers enjoy arguing and philosophising and criticising rival systems. The commoners and kings still listen to their advice and take them with a grain of salt until they come true. In the 4th age astrology was as serious as religion and occupation. By 5th age it is a fringe art just making a come back in it's new form with lots of maths and less super naturalism and other omens. Most popular ones are charlatans. There are a few accurate ones who prefer to hide and make money and hope no kings notice them. A few serve kings but foolish kings have the most and these astrologers get murdered in court most especially if they make errors. Gods in 4th age are shown in control mapping out destinies through arcane science exactly. In the 5th age are shown gambling or gaming with the fates of mortals as pawns while drinking or making foolish bets.