Here you can find the source of diffDate(d2)
Number.prototype.diffDate=function(d2){ var d1=this; var diff1=new Date(d1.dateFormat()).getTime(); var diff2=new Date(Number(d2).dateFormat()).getTime(); var msdiff=Math.abs(diff1-diff2); var daysDiff=Math.floor(msdiff/(1000*60*60*24)); return daysDiff; }
Date.prototype.diffDays = function (date) { var diffMs = (this.getTime() - date.getTime()); return Math.round(diffMs / 86400000); };
Date.prototype.diffHours = function (date) { var diffMs = (this.getTime() - date.getTime()); return Math.round(diffMs / 3600000); };
Date.prototype.diffMinutes = function (date) { var diffMs = (this.getTime() - date.getTime()); return Math.round(diffMs / 60000); };
Date.prototype.diffSeconds = function (date) { var diffMs = (this.getTime() - date.getTime()); return Math.round(diffMs / 1000); };