[Dart] 어제, 오늘 구분하기

final DateTime now = DateTime.now();

DateTime dateTime = DateTime(year, month, day);

if (!dateTime.isBefore(DateTime(now.year, now.month, now.day))) {
    // 오늘
} else if (!dateTime.isBefore(DateTime(now.year, now.month, now.day - 1))) {
	// 어제
}