Hi Steve,
So sorry for the long delay. I hope you were able to locate the OnGetDayFormat event, which allows you to do what you wish. For example, the following event handler colors May 4 green in honor of Grogu (Baby Yoda).
procedure TForm7.RzCalendar1GetDayFormat(Sender: TObject; DayDate: TDateTime; Year, Month, Day: Word; var DayColor,
DayFontColor: TColor; var DayFontStyle: TFontStyles);
begin
if ( Month = 5 ) and ( Day = 4 ) then
begin
DayColor := clGreen;
DayFontColor := clWhite;
end;
end;
Ray