The Subetapedia states the following:

However for the last 5 years, including this year, Vesnali has lasted longer than a week. It usually lasts around 9-10 days. And personally, I am 110% ok with a longer event. I LOVE Vesnali and the amazing items the art staff make for us each year, and honestly would fine the event less enjoyable if we only had a week to try to get everything done.

I just think the Subetapedia should be edited to say 'around one week' instead of something so specific that is not actually followed...

Updated! :)