What is "reasonable" time in Colorado

[Dave Meyer]

I have a broken boiler/hot water system, and unfortunately the needed parts are nowhere to be found. I bought the parts and did (extremely expensive) rush shipping to get the parts here ASAP. From time of tenant reporting the issue to repair will ideally be about 48 hours, but may be an extra day if the shipping is delayed for any reason. 

Is this considered 'reasonable time' in Colorado law? There is truly nothing else I can do to speed this up, but want to be prepared in case a tenant asks about prorated rent.