How to pass a value from a directive to a component?

Question

Vue.js

component part:

<input :name="'bankingsInput['+index+'][invoice_date]'" type="text" v-model="row.invoice_date" class="form-control" v-datetimepicker="row.invoice_date">

directive

Vue.directive('datetimepicker', {
            bind: function (el, binding, vnode) {
                console.log(this)
                console.log(vnode)
                $(el).datetimepicker(datetimepickerDefaults)
                $(el).data('DateTimePicker').date(moment(binding.value, 'DD.MM.YYYY'))
                $(el).on('dp.change', function (event) {
                    vnode.context.$emit('input', event.date || null);
                });
            }
        });

the value does not change...
And yes, I understand that this is done by the component. I want to understand why the directive does not work.