app.component.html

<form #datePickerForm>
  <mat-form-field>
    <input matInput [min]="minDate" [matDatepicker]="picker" placeholder="Choose a date" #pickerInput [formControl]="date">
    <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
    <mat-datepicker #picker></mat-datepicker>
    <mat-error *ngIf="date.invalid">{{getErrorMessage(pickerInput.value)}}</mat-error>
  </mat-form-field>
</form>