[Solved]-Having trouble incrementing X axis by Month in Highchart-Highcharts

Highcharts support the UTC date format in ms as you said. DateTime can be converted using Date.UTC in javascript:

var date = new Date(d.addMonths(1));
var x = Date.UTC(date.getYear() + 1900, date.getMonth(), date.getDate());

Also you have to use tickInterval for xAxis to make sure the intervals are in months:

tickInterval: 30 * 24 * 3600 * 1000 // (30 days, 24 hours, 3600 seconds, 1000 milliseconds)

Here's the DEMO