public TimePeriod(PointInTime begin, PointInTime end)
{
// automatically use the smaller value as period start
if ((begin.Hour * 100 + begin.Minute) > (end.Hour * 100 + end.Minute))
{
Begin = end;
End = begin;
}
else
{
Begin = begin;
End = end;
}
}
#endregion constructor