onDateChange(event: any): void {
  const inputDate = event.target.value;  // Get the value from the input

  // Convert to Date object
  const date = new Date(inputDate);

  // Validate if the date is valid
  if (this.isValidDate(date)) {
    // Call your function if the date is valid
    console.log("Valid date:", date);
    this.someFunction();
  } else {
    console.log("Invalid date");
  }
}

isValidDate(date: Date): boolean {
  return !isNaN(date.getTime()); // Returns false if the date is invalid
}

someFunction(): void {
  // Your custom logic here
}