When I left the scheme 18 months ago it was 3 weeks and a day from when the payment was due.
On my normal payment day I got the full 3 weeks but didn’t get the day, I did try to clarify this with pip but couldn’t get a clear answer from them.
It took around a week to 10 days before I got a letter explaining how my money would now be paid to me direct bundled in with the payment of the daily living component.