Custom Function: Month Check

This Custom Function must be implemented by a system administrator before it can be used in a report. Contact the System Administrator for more information.

Returns true if the provided date value is within a full specified month, or a specified month to date. Returns false otherwise.

This function is intended to be used for conditional aggregates. If one wanted to calculate the sum of one data field within the bounds of a given month or month to date, they would use this structure:

=AggSum( If( MonthCheck( {dateField}, monthsBack, toDate ), {fieldToSum}, 0))

Arguments

1. dateValue — A date, dateTime, or date string that will be inspected to see if it is within this year to date.
2. monthsBack — Number of months back from current month. A value of 0 would be “this month”, 1 would be “last month”, etc.
3. toDate — Boolean value, set to true to calculate month to date for the specified month, set to false to use the full month.

Program Code

//create return value and grab user input
bool retVal = false;
DateTime myDate = DateTime.Parse(args[0].ToString());
int monthsBack = Convert.ToInt32(args[1].ToString());
bool toDate = Convert.ToBoolean(args[2]);
//subtract appropriate amount of months from today's date
DateTime dateBound = DateTime.Today.AddMonths(-1 * monthsBack);

//create boundary day - this will be last day of month, or current day number if toDate flag is set
int boundaryDay = toDate ? dateBound.Day : DateTime.DaysInMonth(dateBound.Year, dateBound.Month);

//return true if input date is within specified month/MTD
DateTime firstDay= new DateTime(dateBound.Year, dateBound.Month, 1);
DateTime lastDay = new DateTime(dateBound.Year, dateBound.Month, boundaryDay);

if(myDate >= firstDay && myDate <= lastDay)
{
  retVal = true;
}

return retVal;