Upvote:1
Your visa allows you to stay for up to nine days, between 7 and 30 May. Your plan is to stay for eight days from 10 to 17 May. That is up to nine days and between 7 and 30 May. Of course that is valid.
Upvote:3
You have been given extra days of validity for just this purpose. Business meetings may be shifted on short notice, etc.