Implementing jQuery DatePicker in Bootstrap modal

jQuery version of @crftr answer

var enforceModalFocusFn = $.fn.modal.Constructor.prototype.enforceFocus;
$.fn.modal.Constructor.prototype.enforceFocus = function() {};
try{
    $confModal.on('hidden', function() {
        $.fn.modal.Constructor.prototype.enforceFocus = enforceModalFocusFn;
    });
    $confModal.modal({ backdrop : false });
}
catch (error) {
    if(error.name != 'ReferenceError')
        throw error;
}

This is because the modal enforces focus on itself. Here is a solution for this as mentioned here . Add the below script to your js file. That's it.

Working Demo

jQuery

// Since confModal is essentially a nested modal it's enforceFocus method
// must be no-op'd or the following error results 
// "Uncaught RangeError: Maximum call stack size exceeded"
// But then when the nested modal is hidden we reset modal.enforceFocus
var enforceModalFocusFn = $.fn.modal.Constructor.prototype.enforceFocus;

$.fn.modal.Constructor.prototype.enforceFocus = function() {};

$confModal.on('hidden', function() {
    $.fn.modal.Constructor.prototype.enforceFocus = enforceModalFocusFn;
});

$confModal.modal({ backdrop : false });

For Bootstrap 4:

replace : $.fn.modal.Constructor.prototype.enforceFocus
By: $.fn.modal.Constructor.prototype._enforceFocus