Is it meant to reset the empeg time from RDS? As mine clearly isnt

No. It doesn't set the empeg's time based on RDS time. But in my area, RDS time is always wrong. Yeah, the RTC on the empeg isn't perfect, but it's much more reliable than the stations around here who can't be bothered with nuisances like "daylight savings time" or even "setting the clock on their RDS transmitter." But they do seem to spend lots of time coming up with lame advertisements for their morning show to embed in the RDS info scroll area.

Or, in other words, the ability to disable RDS is a god^H^H^HLordsend.