David Irving gives slightly different dates in his book 'The Rise And Fall Of The Luftwaffe - The Life Of Erhard Milch'. He talks about it coming into existence on 15 May 1933 with the Order d/d 10 May 1933. This is cross referenced to Karl-Heinz Voelker's book
'Dokumente und Dokumentarfotos zur Geschichte der deutschen Luftwaffe'.
If you don't have a copy of Irving's book, it is available via his website as a free PDF download:
http://www.fpp.co.uk/books/Milch/index.html