How early can you try to change flights at airport kiosk?

[djfuzz]

So I'm on a B class fare MEL-SYD later this evening, but have had my day in Melbourne clear up considerably.

Was thinking of trying to see if I could just head to the airport and get an earlier flight, as these seem to be available for B class fares when checking in at the kiosk - but how early is too early to simply change at the kiosk? Can I head in early this afternoon (>T+3 hours) or would I need to get such a change made through my travel agent?

 

[medhead]

I saw someone able to change their flight via the kiosk about 4.5 hours prior to the original scheduled flight.

 

[NM]

If its a B fare, then should not have any penalty/fee for changes, so why not just head to the Qantas Club service desk and ask them to get you on an earlier flight (assume no checked bag of course)?

 

[samh004]

And what was the result?