A method for maintaining timing accuracy in a mobile device includes: obtaining a range estimate using a signal received from a timing information source via a communication unit of the mobile device; obtaining position and velocity estimate information for the mobile device from a source of position and velocity information separate from the timing information source, the position and velocity estimate information being obtained from at least one sensor of the mobile device, or via a communication unit of the mobile device using a Vehicle-to-Everything wireless communication protocol, or a combination thereof; determining estimated clock parameters based on the position and velocity estimate information and the range estimate; and adjusting a clock of the mobile device based on the estimated clock parameters in response to a position-and-velocity-assisted timing uncertainty corresponding to the estimated clock parameters being below a timing uncertainty threshold.