public bool RuntimeValidation(ref string error) { if (MorningTimePeriod.Overlaps(MiddayTimePeriod)) { error = "Morning period overlaps midday period!"; return(false); } if (MorningTimePeriod.Overlaps(AfternoonTimePeriod)) { error = "Morning period overlaps afternoon period!"; return(false); } if (MiddayTimePeriod.Overlaps(AfternoonTimePeriod)) { error = "Midday period overlaps afteroon period!"; return(false); } return(true); }