Lt. Columbo's "It didn't take me until July"

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?

Solution 1:

This is a call back to an earlier quote within the episode, and thus only makes sense within the context of the episode -

Milo Janus: I don't care what you think. I don't care what you suspect. I don't care what visions you see when you look at your cigar ashes because I'm innocent. I have an alibi for the time Gene Stafford died and you can huff and puff on that rotten cigar until next July and you'll never prove otherwise.

Lt. Columbo: I wouldn't count on that.