Both are grammatically correct. "When is the interview" is singular, asking when one interview is. The plural one talking about numerous interviews is "when are the interviews."
To interview, I interview, he interviews, I interviewed.
Interviews
Most of the interview is formal.
how to face airline interview
Daniel Molloy
On the Spot Interviews - 2011 Fivel Stewart Interview was released on: USA: 21 November 2012
He interviews various stars every night.
No
The Nanny Interviews - 2011 The Manny Interview 1-2 was released on: USA: 7 December 2011
On the Spot Interviews - 2011 Marc Bowman Interview DEAFestival was released on: USA: 2 October 2012
the interview is divide into two section one is formal and to is inforaml
a waiter is incharge of the interview