How to change basic sun position in editor (not PIE)?

After creating a blank first_person project - the sun posistion rendered in the editor viewport (not during PIE!) has an arbitrary yaw and pitch (rotation).

If I CLEAR the light_source from SkySphereBlueprint (BP_Sky_Sphere) I can change the sun pitch/yaw
using the sun height and Transform.Rotation.Z.
However, want to do this WITH a Directional Light Actor assignment.

So, somewhere (possibly within in BP_Sky_Sphere) there is a default yaw/pitch applied when a Directional Light Actor is is in use, however, I just can’t find it anywhere.

How can I change the default sun position in the editor (not PIE) when a Directional Light Actor (light source) is assigned?

For example, I want the editor to start with the sun below the horizon, not above it.