private DateTime GetYesterday()
{
TimeSpan spanToSubtract = new TimeSpan(1, 0, 0, 0);
DateTime dateResult = DateTime.MinValue;
if (DateSubtractWontBeLessThanMinDate(referenceDate, spanToSubtract))
{
dateResult = new DateTime(referenceDate.Year, referenceDate.Month, referenceDate.Day, 0, 0, 0);
dateResult = dateResult.Subtract(spanToSubtract);
}
else
{
FrequencyError newError = new FrequencyError(FrequencyErrorTypes.ResultLessThanDateMin);
errors.Add(newError);
}
return dateResult;
}
private DateTime GetTomorrow()
{
TimeSpan spanToAdd = new TimeSpan(1, 0, 0, 0);
DateTime dateResult = DateTime.MaxValue;
if (DateAddWontExceedMaxDate(referenceDate, spanToAdd))
{
dateResult = new DateTime(referenceDate.Year, referenceDate.Month, referenceDate.Day, 0, 0, 0);
dateResult = dateResult.Add(spanToAdd);
}
else
{
FrequencyError newError = new FrequencyError(FrequencyErrorTypes.ResultGreaterThanDateMax);
errors.Add(newError);
}
return dateResult;
}
private DateTime GetNextYear()
{
DateTime resultDate = DateTime.MaxValue;
if (YearNotGreaterThanMaximumYear(referenceDate.Year + 1))
{
resultDate = new DateTime(referenceDate.Year + 1, 1, 1, 0, 0, 0);
}
else
{
FrequencyError newError = new FrequencyError(FrequencyErrorTypes.ResultGreaterThanDateMax);
errors.Add(newError);
}
return resultDate;
}
private DateTime GetNextMonth()
{
DateTime resultDate = DateTime.MaxValue;
if ((referenceDate.Month != 12) || (YearNotGreaterThanMaximumYear(referenceDate.Year + 1)))
{
DateTime nextMonth = GetThisMonth();
nextMonth = nextMonth.Add(new TimeSpan(27, 0, 0, 0));
int monthOfPriorDate = nextMonth.Month;
int monthOfCurrentDate = monthOfPriorDate;
while (monthOfCurrentDate == monthOfPriorDate)
{
nextMonth = nextMonth.Add(new TimeSpan(1, 0, 0, 0));
monthOfCurrentDate = nextMonth.Month;
}
resultDate = new DateTime(nextMonth.Year, nextMonth.Month, nextMonth.Day, 0, 0, 0);
}
else
{
FrequencyError newError = new FrequencyError(FrequencyErrorTypes.ResultGreaterThanDateMax);
errors.Add(newError);
}
return resultDate;
}
private DateTime GetLastYear()
{
DateTime resultDate = DateTime.MinValue;
if (YearNotLessThanMinimumYear(referenceDate.Year - 1))
{
resultDate = new DateTime(referenceDate.Year - 1, 1, 1, 0, 0, 0);
}
else
{
FrequencyError newError = new FrequencyError(FrequencyErrorTypes.ResultLessThanDateMin);
errors.Add(newError);
}
return resultDate;
}
private DateTime GetLastMonth()
{
int priorMonth = referenceDate.Month - 1;
int yearOfPriorMonth = referenceDate.Year;
if (priorMonth == 0)
{
priorMonth = 12;
yearOfPriorMonth -= 1;
}
DateTime resultDate = DateTime.MinValue;
if (YearNotLessThanMinimumYear(yearOfPriorMonth))
{
resultDate = new DateTime(yearOfPriorMonth, priorMonth, 1, 0, 0, 0);
}
else
{
FrequencyError newError = new FrequencyError(FrequencyErrorTypes.ResultLessThanDateMin);
errors.Add(newError);
}
return resultDate;
}