public void Can_Get_Start_Of_Month() { var today = new PersianDate(1388, 4, 20); var weekend = today.StartOfMonth(); Assert.That((int)weekend.DayOfWeek, Is.EqualTo((int)DayOfWeek.Monday)); Assert.That(weekend.Year, Is.EqualTo(1388)); Assert.That(weekend.Month, Is.EqualTo(4)); Assert.That(weekend.Day, Is.EqualTo(1)); }