index.js

// In an attempt to reproduce http://stackoverflow.com/questions/37432676/node-js-sequelize-orm-date-issue...

const Sequelize = require('sequelize')
const connection = new Sequelize('so_schema', 'root', '')

const customer = connection.define('customer', {
  dob: Sequelize.DATE
})

connection.sync({
  force: true
}).then(() => {
  const dob = new Date('1990-10-27')
  console.log(`Creating customer with dob: ${dob}`)
  return customer.create({
    dob: new Date('1990-10-27')
  })
}).then(createdCustomer => {
  const {id} = createdCustomer.dataValues
  return customer.findOne({
    where: {
      id
    }
  })
}).then(foundCustomer => {
  const {dob} = foundCustomer.dataValues
  console.log(`Found customer with dob: ${dob}`)
})

output.txt

Creating customer with dob: Sat Oct 27 1990 01:00:00 GMT+0100 (BST)
Executing (default): INSERT INTO `customers` (`id`,`dob`,`createdAt`,`updatedAt`) VALUES (DEFAULT,'1990-10-27 00:00:00','2016-05-25 09:24:41','2016-05-25 09:24:41');
Executing (default): SELECT `id`, `dob`, `createdAt`, `updatedAt` FROM `customers` AS `customer` WHERE `customer`.`id` = 1;
Found customer with dob: Sat Oct 27 1990 01:00:00 GMT+0100 (BST)