Some demonstrative embodiments include apparatuses, devices, systems and methods of synchronizing time. For example, an apparatus may include a GNSS receiver to output GNSS measurements, and an output-timing signal including a plurality of pulses based on a clock of the GNSS receiver; an IMU to output inertial measurements, the IMU including a magnetometer to output magnetometer measurements; an antenna to emit an electromagnetic signal based on the output-timing signal, the electromagnetic signal to be measured by the magnetometer; and a processor to process the GNSS measurements and the inertial measurements, to detect in the magnetometer measurements one or more detected pulses of the output-timing signal, to determine a time delay between a clock of the IMU and the clock of the GNSS receiver based the detected pulses, and to adjust a time-base of the inertial measurements to a time-base of the GNSS measurements based on the time delay.