Many times a meeting is scheduled for every 2nd Tuesday or 3rd Friday etc. of each month, but without a calendar how do you know the date?
OrdinalDay will tell you.
OdinalDay (ordinal;theMonth;theDay;theYear)
Let ( [
blankDays = DayOfWeek ( Date ( theMonth ; 1 ; theYear ) ) - 1 ; // Days of the first week in the previous month
dateFirstWeekSunday = Date ( theMonth ; 1 ; theYear ) - blankDays ; // The date of Sunday in the first week of the month
addWeek = If ( theDay > blankDays ; ( ordinal * 7 ) -7 ; ordinal * 7 ) ; // If the target day is in the first week of the month don't add anything otherwise add the requested weeks
resultDate = dateFirstWeekSunday + theDay + addWeek - 1 // Starting from the first Sunday of the month add the calculated days
] ; // end let variable declaration
resultDate
) // end let