  We analyze $K^0-\bar{K^0}$ oscillations in space in terms of propagating wave
packets with coherent $K_S$ and $K_L$ components. The oscillation probabilities
$P_{K^0 \to K^0} (x)$ and $P_{K^0 \to \bar{K^0}} (x)$ depending only on the
distance $x$, are defined through the time integration of a current density
$j(x,t)$ . The definition is such that it coincides with the experimental
setting, thus avoiding some ambiguities and clarifying some controversies that
have been discussed recently.
