Timecoding systems, methods and data structures are described which, in some embodiments, permit a true time to be ascertained from media samples whose timecodes contain an amount of drift which can arise from having non-integer frame rates. Inventive methods incorporate the use of an offset parameter that describes a time difference between a timecode and a true time associated with a media sample. The inventive approaches can be incorporated with and used compatibly in connection with current timecoding paradigms such as SMPTE timecode and the like. Further embodiments permit timecoding to take place at the field level of a frame. This can permit true-time calculations to be done to ascertain the true time associated with individual fields of a frame. In addition, other embodiments provide novel counting compensation methods that are directed to reducing the drift that can be associated with media samples that are sampled at non-integer frame rates.