Date picker max date time is not inclusive - datepicker

Question

I'm using bootstrap datepicker.
I'm setting the minimum date to the current date and the max date to December of next year.
minDate = new Date();
minDate.setDate(1);
maxDate = new Date();
maxDate.setFullYear(maxDate.getFullYear() + 1);
maxDate.setMonth(12);
maxDate.setDate(0);
maxDate.setHours(23,59,59);
$('#startDateInput').datepicker({
format : "MM yyyy",
viewMode : "months",
minViewMode : "months",
startDate : minDate,
endDate : maxDate
});
$('#endDateInput').datepicker({
format : "MM yyyy",
viewMode : "months",
minViewMode : "months",
startDate : minDate,
endDate : maxDate
});
I'm reading the startdate and end date from the datepicker as below:
var startDateString = $('#startDateInput').val();
var startParts = startDateString.split(' ');
var startEpoch = new Date(parseInt(startParts[1]) , monthsArray.indexOf(startParts[0].toLowerCase()), 01).getTime();
document.getElementById('startDate').value = startEpoch;
var endDateString = $('#endDateInput').val();
var endParts = endDateString.split(' ');
var endEpoch = new Date(parseInt(endParts[1]) , monthsArray.indexOf(endParts[0].toLowerCase())+1,0,23,59,59).getTime();
I store the epochs in the database. When I retrieve the dates and show it in the edit form, I'm doing this
if ($('#object').val()) {
var stDate = new Date(Number("${object.startDate}"));
var enDate = new Date(Number("${object.endDate}"))
$('#startDateInput') .datepicker('setDate', new Date(stDate));
$('#endDateInput').datepicker('setDate', new Date(enDate));
}
Let's say I've selected dec 2019 as input today and saved it. Later when I edit the same form, the endDateInput is not filled because the end date is not inclusive, I suspect.