In an elapsed-time meter, which comprises indicating digit wheels, which are mounted in a housing and operable by an electric motor via an interposed transmission, the rotor of the drive motor is rotatably mounted at one end in a partition contained in the housing and at the other end in a mounting plate, which on the side that is remote from the partition carries the transmission and which is integrally formed with resilient lugs, which cooperate with detent noses carried by the partition to detachably fix the mounting plate in position.