A very long time in some cases but I'm speaking from non-Honda experience.

If it's low on fluid that will be the likely cause - it should be at the top or 2nd line marked on the reservoir, not above - and if it is leaking, keep it topped up so the pump lasts as long as possible.

If for some reason you aren't using Honda PS fluid, you should be as not only will the pump not work as well with anything else but it will leak if you don't use the Honda stuff.

Just to be clear, when you say it makes the groaning/whining noise (not belt squeel) does it do it all the time as you're turning the wheel or only once you've turned the wheel quite a ways in one direction - nearing the "lock" to the left or right?

It's normal for most, if not all, PS pumps to make some noise when you turn the wheel to the left or right and near or reach lock (as far as it will go).