title: Calculate number of days between two dates if condition in another column is met
body: <p>I need help with creating a formula for a status sheet (I'm horrible with if statements).  I have three columns, Status, Start Date and Completed Date.  I need a formula that will calculate the days between start and completed dates if the status is equal to Completed or Cancelled.  If the status is not either of those it needs to calculate between start date and [today].  Is this possible?  </p>