title: Oracle SQL Return all records within days of date
body: <p>I am hoping that somebody can help me out with this question.</p>
  
  <p>The following SQL returns just the records in a given table that are specifically 20 days from current.</p>
  
  <p>Last_Mod_Date = TO_DATE(SYSDATE - 20)</p>
  
  <p>Using similar theory can somebody help me determine how to return all records within the past 20 days range?</p>
  
  <p>Thanks! </p>