Let's build a setting, one post at a time.

[Lanefan]

The four moons have cycles etc. thusly:

Uripan: a full moon every 20 days*, moves through the sky in the same direction as the sun
Nehush: a full moon every 40 days*, moves through the sky "backwards", in the opposite direction to the sun
Koia: never has a "full moon" or any other phases: it isn't lit directly by the sun as it is constantly eclipsed by the host planet (does this under-construction world have a name yet?)
Xalaphera: a full moon every 80 days*, moves through the sky in the same direction as the sun, is smaller in actual size than it appears to the eye and you can talk to Gnomish illusionists (and their deities) to find out why it looks bigger.

The most common calendars are based on phases of Nehush: 9 months of 40 days each, though each culture has its own names for the months.

* - I'm told by an astronomer friend (who is also my DM) that multiple moon systems tend to settle into orbital patterns like this where the orbit-time of each is a direct multiple of the others; I learned this because my own setting also has a multi-moon setup.

 

[pemerton]

The sun (called Uol when people have a need to call it anything other than “the sun”) should have burnt out eons ago. It is kept alive by a massive complex of magic and machinery that thrums at its core. Uol is worshiped by the lizardfolk, who in ages long past were uplifted by the Sun Builders.

The Lizardfolk culture is focussed on physical and mental perfection, The lizard folk believe that one who attains ultimate perfection and lives for 1000 years will transform into a legendary Dragon-khan and fly to Uol.

It was here that were built the 9 dwarven dreadnoughts, the iron ships half a mile long that demonstrate the dwarves military and magical might.

This is a secret of the setting (ie not initially known to the players):

Spoiler

The Dwarven dreadnoughts are powered by captured dragons, imprisoned in the vessels' great engine rooms. This source of power underpins the Dwarves' naval and hence mercantile might. But it puts Uol at risk of sputtering out, with no new Drgaon-khan's to fly to it and maintain/upgrade/replace the machinery that keeps it alight.

 

[CreamCloud0]

Koia the "Hag Moon" of Winter is a dark moon that seems to absorb light rather than reflect it. Thus Koia appears as a dim, obsidian disk against the stars. She is venerated by the Elves and her influence is tied to illusion, shadows, and secrets. Her phases affect dreams, giving rise to prophetic visions and to nightmares.

by far the most common variety of elf in the setting are the sea elves who have extensive underwater communities, though there is a notable number who give up their aquatic abilities in a ritual dedicated to Koia, transforming them into mark of shadow elves in the process and who have gone onto forming most of the surface elven settlements.

 

[TwoSix]

The four moons have cycles etc. thusly:

Uripan: a full moon every 20 days*, moves through the sky in the same direction as the sun
Nehush: a full moon every 40 days*, moves through the sky "backwards", in the opposite direction to the sun
Koia: never has a "full moon" or any other phases: it isn't lit directly by the sun as it is constantly eclipsed by the host planet (does this under-construction world have a name yet?)
Xalaphera: a full moon every 80 days*, moves through the sky in the same direction as the sun, is smaller in actual size than it appears to the eye and you can talk to Gnomish illusionists (and their deities) to find out why it looks bigger.

The most common calendars are based on phases of Nehush: 9 months of 40 days each, though each culture has its own names for the months.

* - I'm told by an astronomer friend (who is also my DM) that multiple moon systems tend to settle into orbital patterns like this where the orbit-time of each is a direct multiple of the others; I learned this because my own setting also has a multi-moon setup.

You grabbed the moon orbit idea before I could. Nice one, I do like the resonance patterns.

 

[el-remmen]

For eons psionic powers were limited to a subset of lizardfolk considered chosen before even hatching (the eggs are marked and those around them are often bombarded with the psychic resonance of embryonic lizardfolk - they are the key ingredient in ancient and forbidden “mind-bombs”) but in the last 7 generations other Peoples have started developing psionic powers and no one knows why. The powers are associated with Uol

 

[TwoSix]

The three common races of Herzia and Vaelos, the Halflings, Gnomes, and Dwarves, have many divisions between their nations and clans. But, they are all united in a common faith and identity worshipping the four moon goddesses. It is rare to find a halfling without a gnome somewhere in their family tree, or a gnome that doesn't have a dwarven ancestor.

 

[Alzrius]

The ant-people live underground, surfacing only rarely due to what they consider to be the harsh light of the sun and moons. Most surface-dwellers are unaware that the ants serve as a buffer between them and deeper-dwelling subterranean threats.

 

[Lidgar]

The ant-people, or Formicans as they call themselves, are ruled by Formica the Ant Queen, a powerful psionicist, that seeks peaceful order in the underground realms. They are at constant battle with the corrupted brethren of the lizardfolk, known as troglodytes, who were banished from the surface world because of some long forgotten sin.

 

[el-remmen]

Troglodytes come in various sorts, including the dreaded Troglodyte Juggernaut who guards their egg chambers (which is also where they keep their treasure)

 

[Tonguez]

One of the dinosaurs of Xandahaal is a tree-dwelling species known as Yiqi by the green elves and called Urds by the halfling settlers. While it has not been confirmed, the Yiqi may be an inteligent species, they are certainly able to use tools, throw stones and may even be trapbuilders.