Upvote:2
If you only arrive in the Schengen area on the 8th, then you're just within the limit. There are 8 dates on which you are present in the Schengen area for any time: the 8th, 9th, 10th, 11th, 12th, 13th, 14th, 15th.
The plan doesn't leave much room for your return flight being delayed or canceled, though.