Book competition to win a copy of Dogfight

Those VERY nice people at Pen & Sword have offered us some books to give away in a competetion.
Here's how it'll work.

1. Answer the simple question on this thread.
2. I will put all the names of the members with correct answers in a hat on FRIDAY 21st June 2013 and choose a winner at randomn.
3. I will PM that person & request their address so P&S can send them a copy.
4. Sorry but P&S have said they'd prefer to only send to UK addresses, sorry to our overseas chums.

To win a copy of this book,Dogfight by Adam Classen answer the question below.

http://www.pen-and-sword.co.uk/Dogfight-The-Battle-of-Britain/p/3900/


Question.
What was the date of Adler Tag (Eagle Day) during the Battle of Britain ?

 

You are the winner of this one, please PM me your name & address so I can pass it onto Pen &Sword so they can send you the book.