Production dates

[Karl]

G'day,
I have a 63 hardtop and the date on the warranty plate is 28M (28th Dec). On the rear axle tag the date is 2MD (I take this as 4th week in Dec 62)
I have a couple of questions:-
1/ seeing that the 28th was a Friday and Christmas day was a Tuesday in 1962 would they be working on the Friday.
2/ The 28th being a date that was allocated for the finished car (that is how I understand it) could it be possible that the car never came out of the factory until the following week or even latter seeing that it was Christmas?
3/ The diff being built in the 4th week of the month could it be a replacement not the original or did they produce the axles and had them assembled into the car within a few days? Oh the assembly plant for the axle is 403.

Many thanks for your help.
Karl.