Set Sun Position realtime on Ecliptic Plane using Unity

I have to develop a sky map interactive wall. The interactive wall consist of atlas night sky with constellations and the realtime position of sun according to month. Code

Users can click the stars to view the constellation's info. On the other hand, the position of Sun appeared according to the current month until users choose manually the months, then the Sun will change its position to the selected month. Below is the sample I need to work on the position of the Sun on ecliptic plane.

https://imgur.com/gNZreig

The thing is I have a problem to sync the realtime data with the position of sun with current time. I have search for astronomical database such as SIMBAD but I don't quite sure how to correlate the database with Unity. Or is there any ways i can cope with this issue? Please leave any ideas or any links that correlate with this issue? I would appreciate it so much =)