You can use a DateFormat, just include intl dependency to your pubspec.yaml
import 'package:intl/intl.dart';
DateTime now = DateTime.now();
String formattedDate = DateFormat("dd/MM/yyyy")format(now);
print(formattedDate);
Depending on what your requirements is, you can look at DateFormat
Some examples taken from DateFormat-class to help you a bit more.
String formattedDate = DateFormat.yMd(); // 7/10/1996
String formattedDate = DateFormat("yMd"); // 7/10/1996
String formattedDate = DateFormat.yMMMMd("en_US"); // July 10, 1996
Also see Similar Question
References