8800 Movement Date not working - any ideas?

I've had a Seamaster 300m from new, bought only in March this year. At a sports event, after much clapping, I noticed that the date displayed had shifted to between the day's date and the next date. I put it down as a one-off quirk of the watch.

Almost one month later, the date has stopped changing overnight. I will be sending this back under warranty. Any thoughts of what I might be told? Might it be covered by the warranty, or will I be told that I've abused the watch? I've always been quite careful about hand position when changing the date, so I can't imagine that its something obviously wrong that I've done.

Has anyone else had this? I imagine its not terribly uncommon, however I haven't found any reports of it online.

Also, I'm really reluctant to send the watch in right now, as my other main watch is in for service too, and I can't bear the thought of not having one of them to wear. Am I likely to damage the watch by waiting a few weeks before sending it in? Its still keeping incredibly good time (approx -0.4s per day).

Many thanks in advance for any replies.

Thank you Donn. I'm new to automatic watches, so this is great to know.

Sounds like it would be something easily covered under warranty. Ship it!

Have you tried pulling out the crown and completing a full cycle of the dates? If you've changed the date before did you ever do that between 9pm to 3am?

Yes - I can do a full cycle of the dates when the crown is in the quick set position. I’ve done it only when the watch is reading approx 6 o’clock.
When the crown is in the time changing position, the date tries to change at midnight, but skips and fails.

Your best bet is sending it in for service asap. This is not a common problem.