I wasn't aware of any waiting period before a dismissal or discharge becomes valid. Are you saying that during a given time period a dismissal or discharge can be challenged? In my experience there may be a lag time before the lender becomes aware of what took place in a Chapter 13 case or at least until the information tickles down to the right department within the bank.
Dismissal is basically voiding the bankruptcy case. It doesnt exist and creditors can make their claims again, including foreclosure on your home.
Discharged is completion of the bankruptcy. A trustee is assigned to your chapter 13 case and approves a payment plan which can last up to 5 years. When all payments are made, the case is discharged.
This is for chapter 13, not chapter 7. A Chapter 7 case usually can be discharged in 3-6 months.
With Chapter 13, you can usually get a mortgage 1 year after discharge. Chapter 7 usually 2 years after discharge.
Hope this helps. Im only familiar with Chapter 7. Start to finish was about 5 months. Kept my house, but discharged 1st and second mortgage, but kept paying on the 1st to stay in the house.