There is no way to know what your accountant did. 100 percent business use: See the IRS tables below. Hes should have used the half year convention (Table A-1) if placed in service in January, unless you had over 40% of depreciable assets placed in service in the last quarter.
The mid-quarter convention.
Use this convention if the mid-month convention does not apply and the total depreciable bases of MACRS property you placed in service during the last 3 months of the tax year (excluding nonresidential real property, residential rental property, any railroad grading or tunnel bore, property placed in service and disposed of in the same year, and property that is being depreciated under a method other than MACRS) are more than 40% of the total depreciable bases of all MACRS property you placed in service during the entire year.
