Julian Date Codes vs Cowl Tag Build Dates
 

In order to determine the days of the week a 69 camaro would be built - we would go to the cowl tag to get the code - so for example 04C.

The April calendar week starts on a monday - so effectively that week could be considered 03E if we look at build dates - OR would it be considered 04A?

Im trying to determine the days of the week a car would be built if it was an 04C cowl date code.

Thoughts and help?

Re: Julian Date Codes vs Cowl Tag Build Dates
 

Eddie
I had the similar issue with my car. It has a 08E on the cowl tag but has a build date of September 3, 1969 according to the NCRS documents. Based on that information I assumed that the weeks would have to start on Friday, Saturday or Sunday to have a September 3 build date with a 08E cowl tag. Right or wrong I then assumed that Sunday was the first day of the week.
Using this layman logic I would assume that a 04C cowl date code would have been built during the week of April 20th to 26th.

Re: Julian Date Codes vs Cowl Tag Build Dates
 

Eddie,

The 1st day of April '69 was a TUESDAY. A car built any day that week, except Monday, would be an 04A car as far as the trim tag is concerned. If that car was built on Monday of the same week, it would have been an 03E (Monday the 31st of March would have been the 5th week of March). Also, it is my understanding that the trim tag date is the date that the car <span style="font-style: italic">began</span> assembly. It may have been completed the same day, but it could have been completed at a later date.

IMO, an 04C car would have had a start build date of 14-18 April.

Ervin,

I belive this is why NCRS shows your car as being completed on 3 Sep vs &quot;08E&quot;. August had 5 different weeks that a car could have been built in. Yours was <span style="font-style: italic">started</span> some where from 25-29 August but, was not <span style="font-style: italic">completed</span> until 3 Sep.

Re: Julian Date Codes vs Cowl Tag Build Dates
 

From my research, each week, A, B, C ect denotes the &quot;calendar&quot; week, not the first 6 days and the second 6 days, etc. IF you look at the calendar for the week in question and there is only one day (other than a Sunday) on the top line, then that &quot;A&quot; build week has only ONE day.

Verne [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]

Re: Julian Date Codes vs Cowl Tag Build Dates
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mockingbird812</div><div class="ubbcode-body">

The 1st day of April '69 was a TUESDAY. A car built any day that week, except Monday, would be an 04A car as far as the trim tag is concerned. If that car was built on Monday of the same week, it would have been an 03E (Monday the 31st of March would have been the 5th week of March). Also, it is my understanding that the trim tag date is the date that the car <span style="font-style: italic">began</span> assembly. It may have been completed the same day, but it could have been completed at a later date.

IMO, an 04C car would have had a start build date of 14-18 April.

</div></div>

I have always been curious about this, and it's great to see some discussion of it. But if this logic is correct my 06B should be 06C. Per the NCRS report, my June 13th build date would have been in the 3rd week of the month.

Re: Julian Date Codes vs Cowl Tag Build Dates
 

Fisher didn't have hard, set rules on the weeks. It was for their purposes, Chevrolet never looked at it.
NOR was not consistent. You can try to force a calendar on it - square peg, round hole.

Go off the production date from the NCRS shipping data.

Re: Julian Date Codes vs Cowl Tag Build Dates
 

OK having said the above - when u have a an 04C car what dated YH wheels would be appropriate for the car. Related to YH, Late Jan wheels are known, Feb, only 2-21 or so wheels, no march wheels that i know of, and april - we have 4-18, 19, 20 I'm not sure of and 4-21 for sure

with the closeness of the date of the wheels and the 04C - getting the right wheel dates is key to the build date.

so what do we use for an 04C? The key to me is the actual build dates of the car.....

Re: Julian Date Codes vs Cowl Tag Build Dates
 

Ed my own car is a 04C build date. I have it written down it would have been the week of April 21-27. I know I did the research on this at least 10 years ago but do not remember how I arrived at that conclusion.

Re: Julian Date Codes vs Cowl Tag Build Dates
 

Eddie, with no YH production from late Feb to mid-April, and (as far as I'm aware) no Z28 production issues caused by a shortage of 15&quot; wheels, Kelsey-Hayes must have produced a large number of YH coded Rallys in the February run. Assuming that the April wheel production dates were scheduled based on monitoring demand for those wheels through March, it's unlikely that stocks would have been allowed to fall too low. This is purely my own opinion, but I would think that an 04C car would be more likely to have the late Feb wheels.
The question of build dates for 04C is key to that opinion though; my reading of the 1969 calendar is that 04C is the week commencing the 14th. My 04A LA car has a Fisher body scheduling number on the trim tag 'Bxxx' and from the NCRS shipping data, the official production date is April 1, 1969. That said, April 28th-30th would be the 5th week and I've not seen an 04E trim tag before (though that doesn't mean there aren't any), unless those dates were counted in 05A?

Re: Julian Date Codes vs Cowl Tag Build Dates
 

Tim, agree totally with your analysis on the YH dates. Likely dated wheel is Feb 24 YH's. Incidently, these feb wheels are the hardest every to find.

Ref the build date interpretation - also agree that is key to the analysis. The 04C car falls right in the middle of this understanding - putting 4-19, 4-20, or 4-21 wheels on is right at the edge of possibility.....no one can argue with the Feb wheel date, that fits with the dated parts prior to the build.

Interesting on your car - the 04A build and the ncrs production date seems to imply the 04A date on the trim tag is defined as the end of the week, not the beginning of the week.

One more point to ponder - the end of march build - march 31st is on monday - so is the cowl tag build date 03E or 04A?