Build date question

[js27]

I just noticed a 70 Challenger Convert in the For Sale section and the fender tag calls out a build date of N0v 24 with a serial number of 199792. My old Challenger was a Nov 20 build date with a serial number of 199928. My question is why was  my serial number 136 cars later  when it was suppose to be built 4 days earlier ??
JS27

[6bblgt]

technically the B20 & B24 are SPDs = "SCHEDULED PRODUCTION DATES"

the purple convertible is a "company" and/or "public relations" car that Chrysler Corp. used for some specific purpose (on a specific date)
- Chrysler "bent" what we see 50 years later as normal/typical rules to suit their needs in regard to their "scheduling"

[js27]

Thanks 6bblgt-I knew that the SPD date were basically only estimates. My cars door jam sticker said Dec,1969. I was just wonder if there was another reason.
JS27

[7E-Bodies]

So they were rolling like 1400+ cars per day from there? I just got curious and ran my tag against the orange one of @js27 and mine being about 1400 or more ahead on a B04 with a stickered date of 11/69. Man, they were cranking them out.