private DateTime TestCronNext(string cron, DateTime date, string expectedDate)
{
var sched = new CronSchedule(cron);
var next = sched.TryGetNext(date);
Assert.IsNotNull(next, "Expected next, CRON: '" + cron + "', date: " + date);
var expected = DateTime.Parse(expectedDate);
Assert.AreEqual(expected, next.Value, "Next date does not match expected.");
return(next.Value);
}