After a long hiatus of not wearing a watch at all, I recently took possession of my dream piece - an IWC Perpetual Calendar. Intricate, complicated, and ironically - unrepentantly analogue. But the mystery deepened. As I opened the box containing the watch I discovered a small glass vial, sealed by wax and containing a tiny, perfectly machined part. 'You, or should I say - your great great descendant will need this on January 1, 2200', said the brand manager in response to my puzzled expression - 'it is the replacement slide for when the calendar year moves into a new century'. That set me thinking. We always assume that digital is the logical evolution of analogue, but could it be a relationship more subtle?