Problems adding events in Flutter Calendar - flutter

Question

I am trying to make a simple calendar app in Flutter. He had no problems installing the dependencies, but when he tried to add events he couldn't. It used Date.Time.now with no problem, but when it tried to do it with a specific date it failed. I would appreciate someone who could help me. Thanks a lot
import 'package:flutter_clean_calendar/flutter_clean_calendar.dart';
class MoonCalendar extends StatefulWidget {
#override
_MoonCalendarState createState() => _MoonCalendarState();
}
class _MoonCalendarState extends State<MoonCalendar> {
DateTime selectedDay;
List <CleanCalendarEvent> selectedEvent;
final Map<DateTime,List<CleanCalendarEvent>> events = {
DateTime (DateTime.utc(2022).year,DateTime.utc(07).month,DateTime.utc(15).day):
[
CleanCalendarEvent(
'Event A',
startTime: DateTime(
DateTime.utc(2022).year,DateTime.utc(7).month,DateTime.utc(15).day,10,0),
endTime: DateTime(
DateTime.utc(2022).year,DateTime.utc(7).month,DateTime.utc(15).day,12,0),
description: 'A special event',
color: Colors.blue[700]),
],
};
void _handleData(date){
setState(() {
selectedDay = date;
selectedEvent = events[selectedDay] ?? [];
});
print(selectedDay);
}
#override
void initState() {
// TODO: implement initState
selectedEvent = events[selectedDay] ?? [];
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
"Calendario",
style: TextStyle(fontSize: 22),
),
Text(
" Lunar",
style: TextStyle(fontSize: 22, color: Color.fromRGBO(56, 215, 199, 1)),
)
],
),
),
body: SafeArea(
child: Container(
decoration: BoxDecoration(
gradient: const LinearGradient(
colors: [
Color.fromRGBO(61, 138, 146, 0.2),
Color.fromRGBO(56, 215, 199, 0.1)
]
)
),
child: Calendar(
startOnMonday: true,
selectedColor: Colors.blue,
todayColor: Colors.red,
eventColor: Colors.green,
eventDoneColor: Colors.amber,
bottomBarColor: Colors.deepOrange,
onRangeSelected: (range) {
print('selected Day ${range.from},${range.to}');
},
onDateSelected: (date){
return _handleData(date);
},
events: events,
isExpanded: true,
dayOfWeekStyle: TextStyle(
fontSize: 15,
color: Colors.black12,
fontWeight: FontWeight.w100,
),
bottomBarTextStyle: TextStyle(
color: Colors.black87,
),
hideBottomBar: false,
hideArrows: false,
weekDays: ['Lun','Mar','Mié','Jue','Vie','Sáb','Dom'],
),
),
),
);
}
} ```