The Breitling Watch Source Forums

Indeed Roff. Not going to fix itself. I'm just intending to give it a bit longer to see how frequent it is.

I'm interested by what you say about mainspring torque, as I had myself conjectured something along those lines - for the two occasions when it happened were mornings after I hadn't worn the watch the previous day. I had wondered if there was some mechanical scenario under which it had enough in the tank to keep ticking but not quite enough to fully engage the date wheel, at least within the normal window.

Date change requires a significant amount of torque (relative to anything else in a watch) because the date change mechanism itself connects with the running train so now the mainspring is driving both date change and the time, and because the date wheel is relatively heavy compared to a single hand. As a result it's entirely possible that a low torque could be an issue, but in a 'new' watch that shouldn't be a practical problem assuming that the correct mainspring has been used.

Interesting. I've a hunch that might be the issue - if so it's the sort of issue which if the watch were worn daily or on a winder wouldn't actually manifest itself (even though it shouldn't be happening).