Upvote:4
I fail to see where would a problem arise.
When you enter the area first, you can show your intent of leaving 88 days later. Not that they will grill a US citizen much.
When you leave the area, you have been there for 88 days.
When you seek to re-enter the area... but you don't. You are transiting airside. And even if you wouldn't, you have a stamp in your passport showing entering the Republic Of Ireland which also shows leaving the Schengen area.