Mod clock is a very neat borderless module holding a ticking clock.
See Mods Admin for instructions on how to install a Mod.
Once installed, you will see it under "Admin > Modules" (tiki-admin_modules.php):
You can assign a this Module to a lateral column (See Module Admin page if needed), or you can include it within a wiki page, using the PluginModule.
The assigned module looks like this:
And if you click on the button with the time, you will get some message like this:
See Mod worldclock to get another type of clock on you tiki site.