Macro To Put Date In Column

I have a macro to put date in column A but I have a run time error 13 type mismatch this is the code I have?

Private Sub CommandButton1_Click()

Dim count As Long
count = 1
For i = 2 To 65536
If Cells(i, 1) "" Then
count = count + 1
End If
Next i

Dim date_row As Date
date_row = Cells(count, 1).Value 'this is where the problem is
date_row = date_row + 1

Sheets("Sheet1").Cells(1, 1)(Rows.count, "A").End(xlUp).Offset(1).Value = date_row