I didn't look up NV's exact wording but my state says "landlord shall commence remedial action after receipt of such notice by the tenant as soon as possible but not later than the following time periods"... I wouldn't be surprised if NV's was similar. That is, the repair must be commenced w/in the specified time period not that it must be completed within that time period. I believe that even the state legislators understand that sometimes repair people don't show up or parts have to ordered and shipped in or other issues that could delay completion of a repair. What they want is the LL to start repairs in a timely manner and not just drag his feet.
So I suspect that you are NOT in violation of state law.