var today = Date.now();
var dayInMs = 24 * 60 * 60 * 1000;
var yesterday = DateTools.delta(today, -dayInMs);
var tomorrow = DateTools.delta(today, dayInMs);
var nextWeek = DateTools.delta(today, dayInMs * 7);

trace("today: " + today);
trace("yesterday: " + yesterday);
trace("tomorrow: " + tomorrow);
trace("next week: " + nextWeek);