noun which may take the genitive case particle 'no', noun
how long since the last time
Used to ask or talk about the length of time since something last happened. Often followed by 〜だ or 〜になる.
彼に会うのはいつぶりだろう。
I wonder how long it's been since I last saw him.
こんなに晴れたのはいつぶりですか。
How long has it been since it was this sunny?