Laurent, as one of those contributors of a “complicated answer” ... and framing this response, of course, as merely an impersonal, technical discussion among software engineers ... I think it might be useful here for me to elaborate on the thoughts that guided my particular suggestion.   (Not to defend, per se, but rather to illustrate ...)

To my way of thinking, an over-arching technical consideration of “a program that takes 24 hours to execute” is that the very non-zero possibility exists that this program might, (koff, koff ... say it isn’t so ... say that my pager didn’t just go off at OMGwhattimeisit?...) run for 23.75 hours.

Oops.™

And so, like it or not, that job must be re-run.   Exactly that job.   ...   Provably that job.

If you have replaced the original source-code ... the code that existed at the precise moment when that job was launched ... with another version of the same source-code, then you by-definition cannot “exactly, provably, re-create” that job.

“Well, okay, is that actually an issue?”   Only the OP can tell, but my “forever err on the side of caution” tacit assumption was that it might be.   And this, for the record, is the thinking that therefore guided my previous suggestion.

“Engineering-appropriate prudence?”   “Feechur?”   “Unnecessary complication?”   Only the OP (and his business case) can know for sure.   And, I think, from an engineering point of view, both opinions stand.