function dateTimeWindow
   windowHandle = figure('MenuBar','none',...
      'ToolBar','none',...
      'Name','Current Date and Time',...
      'NumberTitle','off',...
      'Units','normalized',...
      'Position',[.01 .01 .25 .05],...
      'Tag','mexDateTimeHandle',...
      'HandleVisibility','off');
   uicontrol('Parent',windowHandle,...
      'Style','text',...
      'Tag','date_time',...
      'String',datestr(now),...
      'Units','normalized',...
      'Position',[0 0 1 1],...
      'FontSize',28); 
end