A wireless seismic data acquisition unit with a wireless receiver providing access to a common remote time reference shared by wireless seismic data acquisition units in a seismic system. The receiver can replicate local version of remote time epoch to which a seismic sensor analog-to-digital converter is synchronized. The receiver can replicate local version of remote common time reference to time stamp local node events. The receiver can be placed in a low power, non-operational state over periods of time during which the unit continues to record seismic data, thus conserving unit battery power. The system corrects the local time clock based on intermittent access to the common remote time reference. The system corrects the local time clock via a voltage controlled oscillator to account for environmentally induced timing errors.