If you made it available for rent (on 12/17, that's the date to use for the in-serice date.
Depreciation begins as soon as your property becomes income-generating or is put in service. For instance, if you bought the property on the 1st of June but only began renting it out on the 1st of August after necessary repairs, then you’d begin depreciation in August1.
In more technical terms, whether an asset is considered to be “placed in service” for depreciation purposes depends on its specific function and when it is in a condition or state of readiness and availability for that function. For example, if you acquire equipment for business production, it’s not enough to merely have it delivered to the warehouse. The equipment must be removed from the box and actually used for its intended purpose.
So, the in-service date for depreciation is determined by when the property is ready and available for its intended use, rather than the exact moment it is open for business or generating income.
