It's a bit messy, but you could do this:

=LEFT(A2,SEARCH(" -",A2)-1)*if(len(LEFT(A2,SEARCH(" -",A2)-1))<=5),1,60)*60*24 &" - "&RIGHT(A2,LEN(A2)-SEARCH("- ",A2)-1)*if(len(RIGHT(A2,LEN(A2)-SEARCH("- ",A2)-1))<=5,1,60)*60*24

Hope this helps.

Pete