A set of digital indicators in an electronic display unit of a timepiece are actuated by driving pulses transmitted thereto through respective stages of a multistage frequency divider. A switching mchanism is manually operable to advance certain of these stages, independently of the driving pulses and at a faster rate, to adjust the display. A timer discriminates between short-term and long-term switch reversals to differentiate between a gating signal, giving passage to a train of high-rate stepping pulses, and (a) selection signals identifying an indicator to be stepped or (b) manually produced pulses for adjustment at a slower rate. A protective circuit may be inserted between the switching mechanism and the display-controlling circuitry for preventing the transmission of indication-modifying signals to the display unit in the absence of a special unblocking signal, generated separately, which trips an electronic relay such as a flip-flop into an off-normal condition for the emission of an enabling signal; the flip-flop may be automatically reset to normal, after a predetermined period, in the absence of a manually generated blocking signal. Stationary digital indicators, such as those registering the triggering time of an alarm circuit, may be similarly adjusted.