title: Sequelize grouping by date, disregarding hours/minutes/seconds
body: <p>Hey so im trying to query from a database, using Sequelize (Node.js ORM for postgreSQL), im trying to group by date range, and keep a count of how many items where in that table.</p>
  
  <p>Right now the code i have is</p>
  
  <pre><code> Task.findAll({
      attributes: ['createdAt'],
      group: 'createdAt'
    })
  </code></pre>
  
  <p>But as you can see the grouping only takes into account the exact date (including seconds) so the grouping is actually pointless since no matter what there will be no overlapping items with the exact same second count.
  So i want it to just be group based on day, year and month.</p>
  
  <p>Im assuming that it will have to be something like sequelize.fn(...)</p>