Adding two dates resulting #value error

[aamir]

How can i prevent #value error from this formula

i am adding

01/08/2011 to DATE(YEAR(A1),MONTH(A1)+3,DAY(A1))-1

using

=AND(">="& $A$1,"<="& $E$1)

causing # value error

 

[nise23]

Are all relevant cells properly formatted as dates? The #value error may come from one of the cells being formatted as text which doesn't allow for calculations...

 

[Robert Mika]

If you try to concatenate use this:
=">="&$A$1&"<="&$E$1

 

[Firefly2012]

If not concatenation (see Robert's response) then what result do you expect?