How use Flutter syncfusion calendar with jalali date

you can create your custom one which I think it is the best way

as you can see here

for now there is no way to use Persian(jalali) calendar with syncfusion,

here is what they have said about
.

As of now, we don’t have support for converting the calendar to jalali calendar. We have logged the feature request for the same. We will implement it in any of our upcoming releases. We appreciate your patience until then

but you can make its language to farsi(only language and not the calendar time) with loocalization

MaterialApp(
            //ignore: always_specify_types
      localizationsDelegates: [
        GlobalMaterialLocalizations.delegate,
        // ... app-specific localization delegate[s] here
        SfGlobalLocalizations.delegate
      ],
      //ignore: always_specify_types
      supportedLocales: const [
        Locale('en'),
        Locale('fa'),
        // ... other locales the app supports
      ],
      locale: const Locale('fa'),
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
        home: MyHomePage(),
    );

again, it just changes the language