Date appears as number when add text to the end

I am trying to have my cell show a range of dates, like:
5/25/14 - 5-27/14

I'm trying to use a formula like:
=DATE(2012,5,9) & " - " & DATE(2012,5,9)+2

But when I do this it just appears as:
41038 - 41040

Is there any way to tell excel to format these as dates?