Javascript service

Does anyone know how to convert timestamp to Datetime in Javascript please? thank you so much? 

This is my service that returns dates but in MS i need to bind its output to an SQL query who uses datetime as inputs : 

var currentDate=new Date(Date.now());
var currentWeekDay=currentDate.getDay();
var currentHour=currentDate.getHours();
var currentMonthDay=currentDate.getDate();
var currentMonth=currentDate.getMonth();
var currentYear=currentDate.getFullYear();
var SelectedButton ;
var myStartDate;
var myEndDate ;
var i=currentWeekDay;
var j=currentMonthDay;
var newEntry=new Object ();
if (SelectedButton=="Yesterday"){
myStartDate=currentDate;
myStartDate.setDate((currentDate.getDate())-1);
myStartDate.setHours(06);
myEndDate=new Date(Date.now());
myEndDate.setHours(06);

}
if (SelectedButton=="Week To Date"){
myStartDate = currentDate;
myStartDate.setHours(06);
if(j<i) { myStartDay.setDate(30-(7-i+j));
myStartMonth.setMonth=currentMonth-1;
myStartDate.setHours(06);} else {
myStartDate=currentDate;
myStartDate.setDate(j+1-i);
myStartDate.setHours(06);
}
myEndDate=new Date(Date.now());
myEndDate.setHours(06);
}


newEntry.StartDate= myStartDate;
newEntry.EndDate = myEndDate;

var params = {
infoTableName : "InfoTable",
dataShapeName : "StartEndDate"
};
var result = Resources["InfoTableFunctions"].CreateInfoTableFromDataShape(params);

result.AddRow(newEntry);