title: Convert 360 days calendar into normal Julian day calendar using Pandas
body: <p>I have pandas data frame which looks like below with 30 days in each month. Now I would like to convert this data frame into the regular Julian days calendar and put NA in those days with the missing date (for eg 1/31/2001: NA and so on) and interpolate later. Can any one suggest me the option to handle in pandas ? </p>
  
  <pre><code> Date   X    
  1/1/2001    30.56787109
  1/2/2001    29.57751465
  1/3/2001    30.38424683
  1/4/2001    28.64764404
  1/5/2001    27.54763794
  ......
  ......
  1/29/2001   27.44857788
  1/30/2001   27.16296387
  2/1/2001    28.02816772
  2/2/2001    28.28137207
  2/3/2001    28.38671875
  .......
  .......
  02/29/2001  32.23730469
  02/30/2001  32.56161499
  3/1/2001    31.38146973
  3/2/2001    30.73623657
  3/3/2001    30.81912231
  ......
  3/28/2001   33.7562561
  3/29/2001   34.46350098
  3/30/2001   33.49130249
  4/1/2001    30.91223145
  4/2/2001    30.94335938
  .....
  4/30/2001   30.02526855
  
  ......
  ......
  12/29/2001  27.44161987
  12/30/2001  28.43597412
  </code></pre>