I have been writing article about hide clock at sys tray through taskbar properties. And that’s an easy way to hide or show it, so do the other users. So if you want to make it safer, hide it through Windows registry.
Like usual, if you want to change the registry value, you’ll need to open Registry Editor first.
1. To open Registry Editor, click Start – Run menu, type regedit in text box and then press Enter key.

2. In Registry Editor, drive to HKEY_CURRENT_USER | Software | Microsoft | Windows | CurrentVersion | Policies | Explorer path.

3. In that path, find key: HideClock if you don’t find it. To create HideClock key, right click on right panel, choose New – DWORD value menu and then change the new value name to HideClock. Then change its value to 1 by double click it and then in Value data: box to 1 and then click OK button.

then your Registry Editor will be like picture below.

4. Restart your computer and then look at your systray. Your clock is gone.

You can’t reactivate clock through taskbar properties because its radio check is disabled.
To show it again, just change the HideClock value to 0 or delete that key.
(article no:0119)