validating ionic5 datetime value required code example
Example 1: ion datetime time current set
public date:any = new Date().toISOString();
...
<ion-datetime [(ngModel)]="date"
displayFormat="MMM DD, YYYY HH:mm"
formControlName="myDate">
</ion-datetime>
Example 2: ion input date
<ion-datetime
displayFormat="MM/DD/YYYY"
min="1994-03-14"
max="2012-12-09">
</ion-datetime>