<mat-form-field>
  <input matInput [min]="startDate" [matDatepicker]="startDp" placeholder="Promoção começa em:" disabled [(ngModel)]="productInterfaceService.pi.sales_start_date">
  <mat-datepicker-toggle matSuffix [for]="startDp"></mat-datepicker-toggle>
  <mat-datepicker #startDp disabled="false"></mat-datepicker>
</mat-form-field>