How to get date of specific day of the week in Flutter/dart?

Try this one:

var dayOfWeek = 1;
DateTime date = DateTime.now();
var lastMonday = date.subtract(Duration(days: date.weekday - dayOfWeek)).toIso8601String(); 

With dayOfWeek being 1 for Monday, 2 for Tuesday, and so on.

Try this one:

void main()
{
  var monday=1;
  var now = new DateTime.now();

  while(now.weekday!=monday)
  {
      now=now.subtract(new Duration(days: 1));
  }

  print('Recent monday $now');
}