The important switch from the so-called old B-theory to the new tenseless theory of time (NTT), which had significant implications for the field of tense and indexicals, occurred after Carnap’s era. Against this new background, Carnap’s original inter-translatability thesis can no longer be upheld. The most natural way out would be to modify Carnap’s position according to the NTT; but this is not compatible with Carnap’s metaphysical neutrality thesis. Even worse, Carnap’s work on measurement theory can be used to develop (...) an argument in favour of the A-theory. I argue that there are tensed basic sentences which are needed in order to construct a tenseless system and thus cannot be translated without loss of meaning into tenseless ones (old B-theory) or made true by tenseless facts (NTT). (shrink)