Highcharts columnrange date chart

Question

My goal is to make a chart that tracks user activity. I want it to plot when they first logged on, and when they last logged on.

The data I pass into this function ( var refarray = [...data here...] ) is in string format, meaning I need to parse the dates given to me from the database into a date format, or so I thought. Below you will see my attempt.

function hc_first_last_logon(selector, refarray){
var categories = [];
var Dat = [];

for(var i = 0; i<refarray.length; i++){    // store all user names and data
    categories.push(refarray.name)
    Dat.push([Date.parse(refarray.FirstLogon), Date.parse(refarray.LastLogon)])
}
//console.log(Dat) returns date time objects as expected
var def = {
    chart: { type: 'columnrange', inverted: true },
    legend: { enabled: false},
    title:{ text: "First and Last Log-on"},
    xAxis:{ categories: categories, title:{text: "User"}},
    yAxis:{ type: 'datetime' },
    series:[{name: "First and Last Log-on", data: Dat}]
};
var div = $('#' + selector);
console.log(div);
div.highcharts(def);
return def;}

My intent is for this chart to be versatile, allowing me to choose any number of different users, and get the chart when I click a refresh button on my html page (it queries the database and sends the data to this function).

I suspect that my issue has to do with the date variable, Dat , as it appears that the string and date variable types are not acceptable data inputs for highcharts.

Here's an included screen shot of the errors that I am getting in the returned code. The 10x2 matrix is pretty much all the same, so I'll only include one row. Error #17 corresponds to unacceptable data type, which confirms my suspicions.

Console Results

Any suggestions?

UPDATE: I included highcharts-more.js, and now got rid of the error mentioned above. The date ranges are still a bit off. Below is an image of what's going on now.

Current Chart Situation

Answer 1

Thanks to @Grzegorz Blachliński and his suggestions, I was able to find the issue and resolve it. Here's what went wrong:

1) I did not load highcharts-more.js Including this file resolved the Highcharts error 17.

2) Date needs to be in milliseconds from 1/1/1970. Easy fix putting the dates generated into (datevar).getTime().

3) I did not have a tooltip formatter. I copied one off the internet that got the job done, and it worked!

Here's the code for those interested:

function hc_first_last_logon(selector, refarray){
var categories = [];
var Dat = [];

for(var i = 0; i<refarray.length; i++){    // store all user names and data
    categories.push(refarray.name)
    Dat.push([Date.parse(refarray.FirstLogon).getTime(), Date.parse(refarray.LastLogon)].getTime())
}
//console.log(Dat) returns date time objects as expected
var def = {
    chart: { type: 'columnrange', inverted: true },
    legend: { enabled: false},
    title:{ text: "First and Last Log-on"},
    xAxis:{ categories: categories, title:{text: "User"}},
    yAxis:{ type: 'datetime' },
    tooltip: {
        formatter: function() {
            return new Date(this.point.low).toUTCString().substring(0, 22) + ' - ' + new Date(this.point.high).toUTCString().substring(0, 22)
        }
    },
    series:[{name: "First and Last Log-on", data: Dat}]
};
var div = $('#' + selector);
console.log(div);
div.highcharts(def);
return def;}