Are the dates on a 3 day steelhead permit flexible?

I am taking a guided steelhead fishing trip in March and will purchase a 3 day permit and license. If for some reason the trip is postponed, and I do no fishing at all on the original dates, would the license still be good for the revised dates?
Answer: 
We would need to change the dates before the dates on the current license expire.  A new license would need to be issued with the new dates.  This can be done at no cost.
Answered on: 
Thursday, January 14, 2016 - 2:45 PM MST