I would not be the least bit surprised if your character's birth date was a seed value they used for various calculations and as you said perhaps unlocking certain aspects requires use of astronomy.

Additionally they have implied astronomical events to be related to holidays and religious activities, this may have more physical effects than it appears at first glance. I could see astronomy playing an important role in religion and even maybe something bordering on the "arcane".

And of course it's also a great skill for navigation when open sea travel is discovered.

That sounds more like Astrology than Astronomy, especially the idea that one's destiny is tied to the movement of the stars, but this is a fantasy world so maybe you're right and Elyrian "astronomy" is a mix of the two.

Astrology:
The study of the movements and relative positions of celestial bodies interpreted as having an influence on human affairs and the natural world.

Astronomy:
The branch of science that deals with celestial objects, space, and the physical universe as a whole.

For ancient and early medieval periods there was no distinction. Historically the two weren't treated as separate concepts until relatively recently (1600s on). Due to the fantasy and early to mid medieval setting of CoE I would be surprised if the game treated them as different skills.

Medicine and magic/ritual had a similar thing going on even later in our history. While the magic aspects phased out during the later medieval periods, there was still a lot of religious superstition and essentially nonsense in the medical fields until the early 1900s.

Oh I am fully aware of how amazing and useful Astronomy will be. I will be studying it thoroughly and passing that knowledge on to others through my school so the people of my Kingdom will be highly perceptive of what is going on with themselves and the world around them. It will be a powerful tool.

I am so excited to dive into this skill!

Thanks for your answers. I guess I'm not too far off in my speculations. I see that some of you agree that Astronomy will be a great thing in game.

Given what few snippets we've had and a bit of knowledge of Snipehunter's previous work on Revival, I think I have a good idea of just how the skill will be interacting with the game.Of course that isn't to say these two games are exactly synonymous, but I think there's a reason Caspian made him the lead designer.

I can only speculate with the rest of you, but I believe beyond the practicalities of navigation, tracking seasons in our binary star system and the like, understanding the skill in context with the lore we've been given alongside the ten year story is key.