1. A method for determining frequency drift of an oscillator, comprising: obtaining a plurality of residual values during an age drift rate calculation period, wherein each of the plurality of residual values corresponds to a difference between an oscillator output signal and a reference signal, wherein said obtaining the plurality of residual values comprises: obtaining a first plurality of correction signals and associated first temperatures during a temperature curve calculation period; determining a correction signal temperature curve that represents an impact of temperature on the oscillator output signal; obtaining a second plurality of correction signals and associated second temperatures during the age drift rate calculation period; determining corresponding temperature model corrected values for each of the second plurality of correction signals based on the correction signal temperature curve and the associated second temperatures; generating the plurality of residual values based on the second plurality of correction signals and the corresponding temperature model corrected values; integrating the plurality of residual values to generate an integrated aging quantity; and determining an age drift rate of the oscillator output signal based on the integrated aging quantity.