PwC B/A Hiring Cycles

Was planning on applying for a few B/A positions at PwC (Atlanta, Chicago, DC-area) that were posted to their website early September but was frustrated to find out that they must have been removed/closed within the last day or so, as I had not yet applied.

Does anyone have insight on the hiring cycle for PwC BAs? I would assume that hiring takes place in two waves - one for fall grad and one for spring grads - but they've got to make 1000s of B/A hires a year. Which is the case?

My main concern is that it'd be a pain if I had to wait months for another set of B/A postings.

Is it common for these opportunities to only be online for a few weeks before they are closed? When might I be able to expect the next set of B/A postings to go online?

Thanks,

Bologna1