I find the evolution from the first perpetual calendar by Kurt Claus (Da Vinci) in 1985 to the Eternal model truly fascinating. I'm deeply impressed by the watch's suitability for everyday use. 
Unlike, say, a Patek Caliber 89 or a Franck Mueller Aeternitas Mega 4, the IWC Eternal is not only more wearable but also more accurate. Incidentally, the date and all other displays change immediately at midnight. It's different with my Da Vinci 375407.
I'm looking forward to watching your livestream!
All the best
Thomas