Investors & landlords

IRS Publication 527, page 23, states:

When you change property you held for personal use to rental use (for example, you rent your former home), the basis for depreciation will be the lesser of the FMV or adjusted basis on the date of conversion. 

FMV

This is the price at which the property would change hands between a willing buyer and a willing seller, neither having to buy or sell, and both having reasonable knowledge of all the relevant facts. Sales of similar property, on or about the same date, may be helpful in figuring the FMV of the property. 

Figuring the basis

The basis for depreciation is the lesser of: 

• The FMV of the property on the date you changed it to rental use; or 
• Your adjusted basis on the date of the change—that is, your original cost or other basis of the property, plus the cost of permanent additions or improvements since you acquired it, minus deductions for any casualty or theft losses claimed on earlier years' income tax returns and other decreases to basis. 

You do not mention a fair market value of the property.  The basis computed by the software was computed based upon the computation of 91 days / 366 days of the year.