For three years it was possible to do without it. But now it's become necessary again. This coming New Year's Eve, the radio controlled clocks will, after 0:59:59, instead of jumping to 1 o'clock at the next tick of the second, pause shortly in order to insert a small portion of extra time: a leap second.
The International Earth Rotation Service (IERS) in Paris has prescribed this addition to coordinated universal time (UTC), as our Earth is again too much out of sync. The Earth lags behind atomic clock time, whose ticking seconds do not pay attention to any earthly fluctuation. This leap second will be dispensed to the German clocks by the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig.
Find all answers to your questions about time at http://www.ptb.de/en/wegweiser/infoszurzeit/index.html