The time of "closure" to me is when the spouse says that s/he is finished w the A. They need to understand that any contact (phone, email, conversation, etc) is poison to your R.
That closure, whether done face-to-face w the OP or solo by the spouse, signals the beginning of recovery.
The recovery period will last at least as long as the duration of the EA/PA.
I will use my D as an example.
At age 20 she formed her first EA with a guy. They dated for just shy of a year then broke up, more his choice than hers. She was heartbroken. All her hopes had been placed in a projected future w him. He moved on within 3 mos; it took her almost a year to recover enough to be interested in guys as dating material again. She tried to pursue by befriending his sister and seeing him while out w her friends. It only hurt more when she realized that he was seeing other girls and that her pursuits only made him laugh. She came out of it a little wiser, a whole lot stronger, and more decerning in what she wants out of life. . . .and with who she will emotionally bond with in the future.
Now I apply that formula to me. Married 28 years. Conflict/withdrawal probably goes back 14 years. Combined EA/PA maybe was 6mos to 9 mos.
Books tell us that the recovery for your R is one month for each year of M. Use the bomb date as the start. Books tell us the start date for A recovery is when the A is disclosed and ended. It took my H about 5 months to finally go ahead and do a solo private goodbye 'cause she never contacted him to have that talk. I am going to count it as a contact, though, because I know it emotionally hurt to admit that it was over. It would have been better if she'd just told him that she was done w him but nothing is ever easy. Anyway, I put his recovery back to zero based on the good-bye date. Now, if she shows up in May, and they chit-chat, he's back to square one again. Every contact is poison. Maybe that's why it's advised to change jobs or move away.
Meanwhile, the clock is still ticking on the R recovery that started in Sept. I can only assume that those recoveries can overlap when one of the mates is making changes and working on the R (DB!!!!)
It's a time to make the changes permanent to last your whole life through.
I hope this helps. It'd be so much easier if we could straighten out these messes without having to deal w A recovery but that's the way it is.
