For me, only a couple of hours
We have the NBN managed by iinet and were down for a couple of hours at the start of the outage.
Interestingly I could ping most of the sites I visit including El Reg (CloudFlare with a time of 57ms); and iinet's own DNS server (with a time of 20ms) but no web traffic. Web pages just timed out.
Incidentally, when I typed in "iinet" my browser's autocorrect changed it to inept. Perhaps it knows that when Mike Malone left inept, it became a bean-counter's company. I also have had some previous business dealings with TPG before the take-over, I don't expect that things will improve much...