Converting Short-term to Long-term after cost segregation study.

[Keaton Railsback]

I’m new to real estate and I’m looking to get started here soon, my only problem is that I’m wanting to have it help with my business taxes. 

My question is: If I buy a couple house in the last couple months of the tax year, just enough time to close and get the cost segregation study done. In that case am I able to say it’s a “short-term” rental if nobody stayed in there and then convert it to “long-term” rental the following year after getting the cost segregation deduction? Or do people actually have to stay 7 days or less?