title: ISDATE producing error for DATE (datatype) value
body: <p>I have a MyDate(datatype DATE) column in My_Table</p>
  
  <pre><code>MyDate
  2016-11-01
  0001-01-01
  2016-08-01
  </code></pre>
  
  <p>When i execute the following query</p>
  
  <pre><code>SELECT  ISDATE(MyDate),* FROM My_Table
  </code></pre>
  
  <p>I am getting the following error</p>
  
  <blockquote>
    <p>Msg 8116, Level 16, State 1, Line 2 Argument data type date is invalid
    for argument 1 of isdate function.</p>
  </blockquote>
  
  <p>I thought the issue may the date <code>'0001-01-01'</code>. But when i execute </p>
  
  <pre><code>SELECT ISDATE('0001-01-01')
  </code></pre>
  
  <p>It is working as expected and produced the result <code>0</code>.(ie not a date)</p>
  
  <p>But</p>
  
  <pre><code>DECLARE @V AS DATE = '0001-01-01' --no error
  SELECT ISDATE(@V) --error
  </code></pre>
  
  <p>This is producing the same error. 
  What i am wrong here?</p>
  
  <p><strong>Edit</strong>:- If i remove the values <code>'0001-01-01'</code> from Mytable, the query <code>SELECT ISDATE(MyDate)</code> is working properly without any datatype conversion.</p>