Credit: IWC Portugieser Tourbillon Day and Night
The day and night sphere is fully shaded at midnight and is fully unshaded at noon. (The tourbillon is dynamic but not accurately realistic.)
Clockskin Download Zip File: IWC Day Night WFD
Apparently the idea for the 2024 Portugieser Tourbillon Day and Night came from a (now former) apprentice at IWC who submitted the design for consideration. Imagine being a young watchmaker in a massive, storied brand like IWC, and raising your hand with a potential new complication for the brand. Then think about the response when you find out that the brand plans to develop and introduce that complication as a standalone pillar as a part of the relaunch of one of their biggest collections. It is proof that great ideas can come from anywhere, if you are willing to listen. [Reference: hodinkee]