blackoutDatesTextStyle property
Specifies the text style for the blackout dates text in calendar.
Widget build(BuildContext context) {
 return Scaffold(
   appBar: AppBar(),
     body: Center(
       child: SfTheme(
         data: SfThemeData(
           calendarThemeData: SfCalendarThemeData(
             blackoutDatesTextStyle: TextStyle(decoration:
               TextDecoration.lineThrough, color: Colors.green)
             )
           ),
         child: SfCalendar(),
         ),
     )
  );
}
Implementation
final TextStyle? blackoutDatesTextStyle;