Simple function to show and hide taskbar clock.
procedure ShowClock(show: boolean);
var TrayWnd, TrayNWnd, ClockWnd : Hwnd;
begin
TrayWnd := FindWindow('Shell_TrayWnd', nil);
TrayNWnd := FindWindowEx(TrayWnd,0, 'TrayNotifyWnd', nil);
ClockWnd := FindWindowEx(TrayNWnd,0, 'TrayClockWClass', nil);
if show then ShowWindow(ClockWnd,sw_show)
else ShowWindow(ClockWnd,sw_hide)
end;