I'm not seeing how that's much of a WTF. When specifying a time duration or interval, you aren't bound to < 60 seconds like you are when interpreting the time on a clock. I think everyone understands this.
Lots of recipes and heating instructions on food packaging use cooking durations in seconds or minutes >= 60. "90 seconds" is easier to read and understand than "1 minute 30 seconds."
And besides, what else is '9-0-Start' supposed to mean to a microwave? The alternative is to just show an error, which would be a far worse UX than just assuming (with high accuracy) that the user meant 90 seconds.
Lots of recipes and heating instructions on food packaging use cooking durations in seconds or minutes >= 60. "90 seconds" is easier to read and understand than "1 minute 30 seconds."
And besides, what else is '9-0-Start' supposed to mean to a microwave? The alternative is to just show an error, which would be a far worse UX than just assuming (with high accuracy) that the user meant 90 seconds.