docs: def create_day_selectbox(name, selected_day=0, ln=None):
      """Creates an HTML menu for day selection. (0..31 values).
  
      @param name: name of the control (i.e. name of the var you'll get)
      @param selected_day: preselect a day. Use 0 for the label 'Day'
      @param ln: language of the menu
      @return: html a string
      """
      ln = default_ln(ln)
      _ = gettext_set_language(ln)
      out = "<select name=\"%s\">\n" % name
      for i in range(0, 32):
          out += "  <option value=\"%i\"" % i
          if (i == selected_day):
              out += " selected=\"selected\""
          if (i == 0):
              out += ">%s</option>\n" % _("Day")
          else:
              out += ">%i</option>\n" % i
      out += "</select>\n"
      return out