title: Sequelize — use UNIX timestamp for DATE fields
body: <p>Is there a way to force Sequelize use UNIX Timestamp as default time format <strong>both</strong> for createdAt/updatedAt timestamps <strong>and</strong> for custom-defined Sequelize.DATE field types?</p>
  
  <p>Thanks!</p>
  
  <p>P.S. I'm using MySQL</p>