CFLib.org – Common Function Library Project

Description:
Takes a day number, month number, and year. Returns a date object of the first occurance of that day in the given month and year. For example, you want a date object for the first Wednesday in November, 2005. In this case, the function returns the date: 11/2/05.

Return Values:
Returns a date object.

Example:

Our Nov CFUG meeting is on #DateFormat(FirstXDayOfMonth(4,11,2005),"dddd, mmmm d")#

Parameters:

Full UDF Source:

<cfscript>
/**
 * Returns a date object of the first occurance of a specified day in the given month and year.
 * 
 * @param day_number 	 An integer in the range 1 - 7. 1=Sun, 2=Mon, 3=Tue, 4=Wed, 5=Thu, 6=Fri, 7=Sat. (Required)
 * @param month_number 	 Month value.  (Required)
 * @param year 	 Year value. (Required)
 * @return Returns a date object. 
 * @author Troy Pullis (&#116;&#112;&#117;&#108;&#108;&#105;&#115;&#64;&#121;&#97;&#104;&#111;&#111;&#46;&#99;&#111;&#109;) 
 * @version 1, March 23, 2005 
 */
function FirstXDayOfMonth(day_number,month_number,year) {
  var start_of_month = CreateDate(year,month_number,1);  // date object of first day for given month/year
  var daydiff = DayOfWeek(start_of_month) - day_number;
  var return_date = "";
  switch(daydiff) {
    case "-1": return_date = DateAdd("d",1,start_of_month); break;
    case "6": return_date = DateAdd("d",1,start_of_month); break;
    case "-2": return_date = DateAdd("d",2,start_of_month); break;
    case "5": return_date = DateAdd("d",2,start_of_month); break;
    case "-3": return_date = DateAdd("d",3,start_of_month); break;
    case "4": return_date = DateAdd("d",3,start_of_month); break;
    case "-4": return_date = DateAdd("d",4,start_of_month); break;
    case "3": return_date = DateAdd("d",4,start_of_month); break;
    case "-5": return_date = DateAdd("d",5,start_of_month); break;
    case "2": return_date = DateAdd("d",5,start_of_month); break;
    case "-6": return_date = DateAdd("d",6,start_of_month); break;
    case "1": return_date = DateAdd("d",6,start_of_month); break;
    default: return_date = start_of_month; break;  // daydiff=0, default to first day in current month
  } //end switch
  return return_date;
}
</cfscript>