title: How do I add time from a database in Rails?
body: <p>I am fairly new to rails, and attempting to add an amount of time to a datetime in the database. The time and time unit both are returned from the database. </p>
  
  <p>So the data is...</p>
  
  <pre><code>start: 11/1/2015 10:45:00
  duration: 75
  unit: "minutes"
  </code></pre>
  
  <p>I want to add the 75 minutes to the start. I know I can do this if I know them already by saying start + 75.minutes, but how do I do this when both the duration and the unit are variables?</p>