bs-datepicker style positioning

im using bs-datepicker and im not able to set its position

 <input class="form-control" #issue_date="ngModel" ngModel id="issuedate_{{row}}" name="issue_date"
                                    bsDatepicker [bsConfig]="{dateInputFormat: dateFormat, containerClass: 'theme-blue ' , orientation: 'top' }"
                                    autocomplete="off" [placeholder]="dateFormat"
                                    [(ngModel)]="rowObj.issue_date" />
                                </td>

i want it to set the datepicker above my input field
by default it is setting it at bottom