Full time to per diem

[Nursing_excellence, ADN, BSN]

I just got offered a new full time position in DOU floor at a bigger hospital than where I am currently working. I am planning on switching to per diem at my current workplace soon as I start working in DOU. My tentative start date for new job is on March 29. At my current job, I am still scheduled until May 2nd. When and how do I tell my current manager this? I am still in the process for my background check and physical exam for my new job. Should I wait til I finish the on boarding process or should I let my manager know now?

 

Also side question, generally, what happens to your accrued PTO? Do you still get PTO as per diem? How many shifts per pay period are required to work as Per diem? (Of course, I am gonna ask this to my manager, but I want to know general rules for this so I have comparison)