How to use a While Loop in SQL to Create a Variable

In need to create an IN clause with a list of dates in it. The list needs to be in descending order. I created a variable named @cols and am trying to populate it with this code:

declare @end date='2016/05/30' 
declare @begin date = DATEADD(month, DATEDIFF(month, 0, @end), 0) ;
declare @curdate date = @end;
print @curdate;
print @begin;

DECLARE @cols NVARCHAR (MAX)

while @curdate >=@begin  -- goes from end of the month to begiing of the month
begin
     select @cols = @cols + ',[' + CONVERT(NVARCHAR, @curdate, 106) + ']';
     select @curdate =  DATEADD(DAY,-1,@curdate ) -- subtract a day
end

print @cols;   
print @curdate;
print @begin;

I'm hoping to get 5/30/16, 5/29/16, 5/28/16 etc (properly formatted of course). The code runs without error however @cols is always empty.