@RickM5 wrote:
.....could someone have declared their "date of conversion" and "in service date" as 12/31/22 and then taken the whole 100% bonus depreciation for 2022?
You would begin to depreciate (recover the cost) on the date the property is placed in service.
Note that residential real estate has a 27.5 year recovery period (i.e., it is depreciated over that time period). Further, the method is straight-line (equal deduction each tax year) and the convention is mid-month. As a result, if you placed your property in service on 12/31/22, it is treated for tax purposes (depreciation) as having been placed in service on 12/15/22 (mid-month).
Also note there is a de minimis safe harbor for tangible property and also for routine maintenance (but neither would be applicable to real estate).
See https://www.irs.gov/publications/p527#en_US_2022_publink100071091
