+/*
+// Definitions for refactored code. TODO: uncomment when done.
+define('INTERVAL_ALL_TIME', 0);
+define('INTERVAL_CURRENT_YEAR', 10);
+define('INTERVAL_PREVIOUS_YEAR', 14);
+define('INTERVAL_SELECTED_YEAR', 18);
+define('INTERVAL_CURRENT_MONTH', 20);
+define('INTERVAL_PREVIOUS_MONTH', 24);
+define('INTERVAL_SELECTED_MONTH', 28);
+define('INTERVAL_CURRENT_WEEK', 30);
+define('INTERVAL_PREVIOUS_WEEK', 34);
+define('INTERVAL_SELECTED_WEEK', 38);
+define('INTERVAL_CURRENT_DAY', 40);
+define('INTERVAL_PREVIOUS_DAY', 44);
+define('INTERVAL_SELECTED_DAY', 48);
+*/
+
+// TODO: Refactoring is needed for this class. Probably by refactoring DateAndTime first, as Period is
+// basically a collection of 2 DateAndTime instances.
+//
+// Second problem is that "today" is (most likely?) server today, so reports may give incorrect dates
+// for browser users in different time zones. Verify and fix this.