A single pacemaker can produce different rates of reentrainment in different overt rhythms.

Using a simple Van der Pol oscillator, we show that periodic events triggered by different states of the oscillator can reentrain at different rates following a phase shift of the Zeitgeber. Such differences can emerge due to waveform distortion during reentrainment, due to masking and due to fitting procedures (e.g. acrophase determination). Therefore, different rates of reentrainment are consistent with single pacemaker models of circadian systems. Likewise, "Fractional Desynchronization" can yield different "ranges of entrainment" in different overt rhythms generated by the same pacemaker.