I have tried many date picker in my angular2 app but none of them is working.Although the date picker is displaying on the view but the value of selected date is not getting
See ng2-boostrap datePicker seems to overwrite ngModel, while the question is different, the answers given to it solved the issue you described for me.
Assuming using typescript, you need to add this to the html markup:
and in the component ts file, you will need to import
import {DATEPICKER_DIRECTIVES} from 'ng2-bootstrap/ng2-bootstrap';
and add the DATEPICKER_DIRECTIVES to your providers list.