CODE EXAMPLE FOR DART

string to datetime flutter

import 'package:intl/intl.dart';

...

var dmyString = '23/4/1999';
var dateTime1 = DateFormat('d/M/y').parse(dmyString);

var mdyString = '04/23/99'; 
var dateTime2 = DateFormat('MM/dd/yy').parse(mdyString);

var mdyFullString = 'April 23, 1999';
var dateTime3 = DateFormat('MMMM d, y', 'en_US').parse(mdyFullString));