When I e-mailed the Doctoral Program Coordinator in March, she said the Admissions Committee was going to meet on Thursday of that week. I'm assuming they meet on Thursday's.
I did not attend an interview, but was told by the Doctoral Program Coordinator that only some professors request interviews with applicants. Some students are admitted without interviews and some aren't. It all depends on your research interest and the professor you'd like to work with.
On Sunday, I received an e-mail from the Associate Dean that they would be in touch "very soon."