As someone with a passing interest in Roman history I thought you might have an interest in this...
http://news.sky.com/story/pompeii-inscription-rewrites-the-history-of-vesuvius-eruption-11527889 (http://news.sky.com/story/pompeii-inscription-rewrites-the-history-of-vesuvius-eruption-11527889)
Innnnnteresting!
That supports a claim made a few years back by a botanist who argued for a slightly later date too because of some pollens she found in the ash that were associated with autumn.
When I was researching my most recent book, in which the eruption figured prominently, I discovered that there is a growing consensus of opinion that the eruption was later in the year than the date Pliny assigned to it.