The time-dependent approach to calculate half-lives for proton-emitting nuclei is reviewed. Doubts about the practicability of this new method are eliminated by showing that it directly leads to the main observable (the average decay rate), that the result does not depend on the prescription used to prepare the initial state or to define the nuclear border and that the method can be applied to low-lying as well as to highly excited states. ©2000 American Institute of Physics.