title: Convert date format from 'm/d/yyyy' to 'yyyy-mm-dd' in a tsv file using a shell script
body: <p>I have a column with a list of dates in a spreadsheet (.tsv) (some cells are blank) like that :<br>
  6/30/1988<br>
   <br>
  1/2/2000<br>
  etc. ...<br></p>
  
  <p>and I want a file.tsv with a list of dates in a column (keeping the blank cells, because it is for an export in a databases and I need the blank cells for my joints) :<br>
  1988-06-30<br>
  <br>
  2000-01-02<br>
  etc. ...<br></p>
  
  <p>I have done some research but as I am a beginner, I don t manage to do it.
  Thanks a lot</p>