Can you show me the code you used calling the GETDAYBOLD event. Maybe I'm not passing the state array correctly.
Here is how I am doing it. This should just bold the current day. Should be real simple.

****INIT****
rdttime = DATETIME()
Local array state1(1)
state1(1)= .F.
thisformset.calendar._olecalendar1.GetDayBold(TTOD(rdttime), 1, @state1)

****GETDAYBOLD****
*** ActiveX Control Event ***
LPARAMETERS startdate, count, state
FOR i=1 TO count
   state(i) = .T.
   startdate = startdate + 1
ENDFOR
this.refresh

I don't get any errors but nothing is bold either. Maybe you can see what I am doing wrong.