def makeBitmap(self, gc, text):
        width, height = gc.GetTextExtent(text)
        bitmap = wx.EmptyBitmap(width + 2*WEEKDAY_PADDING, height)
        mdc = wx.MemoryDC(bitmap)
        mdc.SetBackground(wx.BLACK_BRUSH)
        mdc.Clear()
        mdc.DrawText(text, 0, 0)
        return bitmap

    def DrawBackground(self, gc):
        if self.weekdayBitmaps is None:
            names = dateFormatSymbols.getWeekdays()
            gc.SetFont(self._font, self._thisMonthColour)
            # ICU makes this list 1-based, skip the first empty element
            self.weekdayBitmaps = [self.makeBitmap(gc, n) for n in names[1:]]

        control = self.multiWeekControl.widget
        columnPositions = control.columnPositions
        columnWidths = control.columnWidths
        
        firstDay = GregorianCalendarInstance.getFirstDayOfWeek()
        for day in xrange(7):
            column = day + 1
            dayBitmap = self.weekdayBitmaps[(day + firstDay - 1) % 7]
            width, height = dayBitmap.GetSize()
            dy = min(HEADER_HEIGHT - height, 0)
            if True or columnWidths[column] <= width:
                dx = columnPositions[column]
                gc.DrawBitmap(dayBitmap, dx, dy, width, height)