Production Dates???

[Lyn Islaub]

I recently read a thread in the New Collectors Forum that spiked my curiosity and made me question an assumption I had long considered to be fact.
The question centered around "if I have a Luger with a 'b' suffix, can I assume it was made in February, or March?" The answer was in the affirmative and because that particular Luger series (byf 42) started production with S/N 500 it made sense that if pistols were produced at a rate of about 10,000 a month his byf could have been produced sometime in March.
Up till reading this, I had always been of the understanding that both DWM and Mauser operated under a September 01-August 31st financial accounting fiscal year like many European and US manufacturers and that by January of the new production year several thousand pistols had already been assembled. I cannot remember where I read that factoid, but wondered if any of the rest of you were under the same belief.
Thx, Lyn