How long after receiving a discharge do you have to not report a windfall of income such as winning the lottery or a large inheritance?

180 days from the date of the discharge.

I believe it is 180 days from filing rather than from discharge. If you filed a chapter 7 and received the inheritance or the right to the inheritance within 180 days of filing, then the money should come into the bankruptcy estate. If you already received your discharge, then the trustee may move to reopen your case and bring a proceeding to get the money. However, Trustees, sometimes, try to bring money into the bankruptcy estate that they don't have the legal right to. Lottery proceeds based on a lottery ticket purchased after you filed bankruptcy are not part of the estate, but trustees have been known to go after the money anyway.