I said in less than 30 seconds.IMHO, 30 seconds is too much time to tune on stage.
Here in the winter, before playing, I usually check the tuning a couple times as the instrument acclimatizes to the hall temperature. I've never timed myself, but I can dial it in probably within a 15 to 20 second window. Longer if I'm squinting at a bouncing needle on a meter.