I don't see anything wrong with that. Wikipedia says a Second is defined as the following:
Under the International System of Units, the second is currently defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom.
That could change as well, so as long as it's precisely defined as the time he takes to achieve his current state in time and space, it's perfectly ok.