public void TestSchedules()
{
var s1 = new DailySchedule(23, 55, 0);
var dt = s1.GetNextExecutionTime(_dt1);
Assert.Equal(_dt1.AddDays(1), dt);
var s2 = new EveryHourOnTheHourSchedule();
dt = s2.GetNextExecutionTime(_dt2);
Assert.Equal(_dt2.AddHours(1), dt);
var s3 = new EveryMinuteOnTheMinuteSchedule();
dt = s3.GetNextExecutionTime(_dt3);
Assert.Equal(_dt3.AddMinutes(1), dt);
var s4 = new EveryQuarterOfAnHourSchedule();
dt = s4.GetNextExecutionTime(_dt4);
Assert.Equal(_dt4.AddMinutes(15), dt);
var ts = new TimeSpan(3, 4, 0);
var s5 = new IntervalSchedule(ts);
dt = s5.GetNextExecutionTime(_dt4);
Assert.Equal(_dt4 + ts, dt);
ts = new TimeSpan(7, 5, 0);
var s6 = new WeeklySchedule(ts, DayOfWeek.Monday, DayOfWeek.Wednesday);
//_dt5 is Wednesday (2017, 6, 14, 7, 5, 00)
dt = s6.GetNextExecutionTime(_dt5);
//dt should be next Monday, which is 19/6
Assert.Equal(_dt5.AddDays(5), dt);
dt = s6.GetNextExecutionTime(_dt5.AddDays(5));
//when it's executed on Monday 19/6, next execution should be on Wednesday 21/6
Assert.Equal(_dt5.AddDays(7), dt);
dt = s6.GetNextExecutionTime(_dt5.AddDays(7));
//and after execution on Wednesday 21/6, next one should be 26/6
Assert.Equal(_dt5.AddDays(12), dt);
}