pickDate method
Implementation
Future<DateTime?> pickDate({
DateTime? initialDate,
DateTime? firstDate,
DateTime? lastDate,
}) async {
final now = DateTime.now();
return showDatePicker(
context: this,
initialDate: initialDate ?? now,
firstDate: firstDate ?? DateTime(now.year - 5),
lastDate: lastDate ?? DateTime(now.year + 5),
);
}