https://graph.facebook.com/me/insights/page_impressions_unique/day?access_token={{TOKEN}}&since=1388649600&until=1391241600

• 1388649600 = 1/2/2014 12:00:00 AM GMT-8
• 1391241600 = 2/1/2014 12:00:00 AM GMT-8

returns something that looks like this:

{
  /* previous, next page, etc keys */
  "data": [
    {
      "values": [
        {
          "end_time": "2014-01-03T08:00:00+0000",
          "value": 4
        },
        {
          "end_time": "2014-01-04T08:00:00+0000",
          "value": 1
        },
        {
          "end_time": "2014-01-05T08:00:00+0000",
          "value": 0
        }
        .... /* More 0 values here until Feb 2 */
      ],
      "period": "day",
      "description": "Daily: The number of people who have seen any content associated with your Page. (Unique Users)",
      "title": "Daily Total Reach"
    }
  ]
}

Whereas