I am having a hard time concluding from the A/65C spec how the system_time field in the STT is anything other than GPS time. I do not see how the conclusion has been reached that this field represents UTC time, and so far have been unable to understand the arguments that have been presented in favor of the syste_time field representing UTC time. But I have seen some of the posts claim that the EIT information is UTC time, and nobody has refuted that yet. However, from my reading of the spec, even though the EITs change at 12:00, 3:00, 6:00, and 9:00 UTC time (not GPS time), the actual start times listed in the EITs are themselves expressed in GPS time. That is, the "start_time" field in the EIT is described on page 44 of A/65C as "A 32-bit unsigned integer quantity representing the start time of this event as the number of GPS seconds since 00:00:00 UTC, January 6, 1980".