title: Changing a string to a date
body: <p>Is it possible to change a number to date using excel functions? For example:</p>
  
  <pre><code>1978    1
  1978    2
  1978    3
  1978    4
  1978    5
  1978    6
  1978    7
  1978    8
  1978    9
  1978    10
  1978    11
  1978    12
  </code></pre>
  
  <p>where the right column is the month. I want to convert it to Jan1978;</p>