This is merely a modification of the "Simple Date and Time" plasmoid to make it spread across two lines, much like the last decade or so of a certain desktop shell from the northwestern US of A. Plasma 5, for some reason, does not allow you to change the clock font size as KDE 4.x did, so this is the next best thing if you prefer smaller clock and date texts.

The format of the time and date displays may be editied by changing the format strings inside the plasmoid's .qml files; this one is set to a generic USA-style display.