How to get days 5 days before and 5 days after

I want to query items from a calender list 5 days before current selected date from datepicker, and 5 days after selected value from datepicker?

This code takes the selected datepicker date from users input and add between 8 o'clock to 17 o'clock,

listItemCustom = document.getElementById('datepicker').value;
var listItemFromTime = document.getElementById('timepicker').value;
listItemtoDate = document.getElementById('datepickerto').value;
var listItemToTime = document.getElementById('timepickerTo').value;
var result = listItemCustom + "T" + listItemFromTime + ":00" + "Z";
var result2 = listItemtoDate + "T" + listItemToTime + ":00" + "Z";
fromTime= new Date(result);
var fromTimeConverted = fromTime.toJSON().split('T')[0] + "T08:00:00Z";
toTime = new Date(result2);
var toTimeConverted = toTime.toJSON().split('T')[0] + "T17:00:00Z";
var camlQuery = new SP.CamlQuery('<View><Query><Where><And><Geq><FieldRef Name=\'EventDate\' /><Value IncludeTimeValue=\'TRUE\' Type=\'DateTime\'>' + fromTimeConverted + '</Value></Geq><Leq><FieldRef Name=\'EndDate\' /><Value IncludeTimeValue=\'TRUE\' Type=\'DateTime\'>' + toTimeConverted + '</Value></Leq></And></Where></Query></View>');
camlQuery.set_viewXml();


collListItem = list.getItems(camlQuery);
context.load(collListItem);

listItemCustom : are from Date listItemtoDate : are to Date