Recruiting timelines - full-time banking + PE analyst offers

Hi all working on my firms recruiting timeline for our private equity analyst recruitment timeline and know the process timing has changed since I was in undergrad 5+ years ago.  Ideally want to make our process competitive on timing as our HR team doesn't seem to actually have a pulse on the market. 

- When do investment banks tend to give offers to their junior year summer analysts?  

- When do those offers tend to explode?  

- Do the people who join private equity analyst classes at the megafunds who didn't summer at those firms tend to recruit over the summer and when do they tend to give out offers? 

- Do people who go to private equity analyst classes have to turn down or renege on their banking offers from summer to convert private equity analyst class offers?   

Thanks in advance and perhaps we cross over at some point in the recruiting process.