folder restructuring

lib/extensions/time_of_day.dart

@@ -0,0 +1,9 @@
+import 'package:flutter/material.dart';
+
+extension TimeOfDayExt on TimeOfDay {
+  bool isBefore(TimeOfDay other) => hour < other.hour && minute < other.minute;
+
+  bool isAfter(TimeOfDay other) => hour > other.hour && minute > other.minute;
+
+  TimeOfDay add({int hours = 0, int minutes = 0}) => replacing(hour: hour + hours, minute: minute + minutes);
+}