Showing the week number in date controls in Dynamics AX

To show the week number in date controls, adapt the SysDateLookup form by setting the property ShowRowLabels of the control DaysTable to Yes (which was the default in Axapta 3.0 BTW, so for Axapta 3.0 installations, it is shown anyway.).

Changing the numbering system for weeks

According to the ISO week date system, the first week of the  year is the week containing a Thursday. Whereas in some countries it is more common to see the first week of the year as the one containing January, 1st. The latter is how the date control in standard Dynamics AX is working as you can see below.

To change this, adapt the method drawMonth of form SysDateLookup as follows:

//daysTable.setRowLabel(w,num2str(weekOfYear(
//                                drawingDate+firstDayOfWeek)
//                                ,2,0,0,0)); 
daysTable.setRowLabel(w,num2str(wkOfYr(
                                drawingDate+firstDayOfWeek)
                                ,2,0,0,0));

This will result in following week numbering:

So there is a difference between the function weekOfYear vs wkOfYr in Dynamics AX, which becomes very clear if we create a small job:

static void CalculateWeekOfYear(Args _args) 
{

    ;
  
    info(strFmt("weekofYear 05.01.2010: %1"
               ,weekOfYear(str2date("05.01.2010",123))));  
    info(strFmt("wkOfYr 05.01.2010: %1"
               ,wkOfYr(str2date("05.01.2010",123))));

}
 

Output: