Short Term Capital Gains on Auction Purchased Home

[Brian Points]

Hello All: My partner and I purchased a home at auction. In our home state, there is a 6-month redemption period during which any lien-holders against the property or the prior owner can seek possession of the home. (They would need to pay us the price that we paid plus interest). For that reason, we are not making any capital improvements until the redemption period expires. However, we do have the key and we have the right to lease it out or live in it. My question is this: If we want to flip the home and avoid the short-term capital gains tax penalty, do we need to wait until 12-months from when we acquired the home at auction? Or 12-months from when we possess the deed (at the end of the redemption period)? Is there some type of activity that the IRS is looking for when making this determination? 

Thanks!