I think the listing of forthcoming village events is a very useful idea. However, I suggest that the village website is not the best place for such a list. To be effective, an anti-clash diary has to be readily available to all, including those who either dont have access to the village website or dont choose to look at it.
Is is too old fashioned to suggest a paper diary kept at the Post Office? Such a document would be easily accessible to everyone planning an event and would hopefully prevent those occasions when the village becomes totally gridlocked with residents and visitors trying to find a place to park close to the event they wish to attend.