Heard the following exchange in the Columbo episode An Exercise in Fatality:
Lt. Columbo: You removed the bulb on the phone in the living room so the line wouldn't light up (...).
Milo Janus: Guesswork, supposition, more cigar ashes. What you need is proof. That what you need -- proof.
Lt. Columbo: It didn't take me 'til July, but I got the proof.
Never heard this exact expression before - and a cursory Google search did not yield any useful hits re. its origin or contemporary usage.
What's the origin of the expression - and is it something that a contemporary US English speaker would easily understand?
Can we use something other than "July" (another month of the year, day of the week etc.) to convey the same meaning?