title: 30days before due date in google spreadsheet
body: <p>I have one spreadsheet in which i want to save reminder date which will be 30days before due date. </p>
  
  <p>Please note that the original sheet on which i am working does not has columns "Start_Date" and "End_Date" which are highlighted in yellow color
  in the shared spreadsheet.</p>
  
  <p>Please advice to set 30days before date based on "End_Day" column in shared spreadsheet?</p>
  
  <p>The below is shared spreadsheet for reference </p>
  
  <p><a href="https://docs.google.com/spreadsheet/ccc?key=0AhrpdumTdTjYdENLeU8yWkpNQm93MDJvREl1M3Y1aHc" rel="nofollow">https://docs.google.com/spreadsheet/ccc?key=0AhrpdumTdTjYdENLeU8yWkpNQm93MDJvREl1M3Y1aHc</a></p>
  
  <p>Thank you in advance.</p>