This may seem an elemental question, but here goes: Why is an instantaneous date change in a movement such a big deal, when an instant "jump" on a chronograph (cumulative minute hand, for example) is not? If the argument is that a date wheel that changes instantaneously requires more frequent service than one which gradually engages the gear just before or just after 12 for an event happening once a day, would this not especially be the case when such an event happens every minute? I just find it odd that many chronograph movements have a jumping minute hand but a gradual date change. Can someone enlighten me on how these two aspects are different in their implementation?