Argust Day is that time when the day date in August matches the year date, such as last year it was August 18, 2018. The numbering convention works until after 2031, then who knows what the Yahoo Argus Group will come up with, if any of them are still around. Heck, maybe Yahoo won't be around then either.
Anyhoo, I took an Argus C3 "Brick" with the 50mm f3.5 lens, and loaded it with Ilford Delta 100 for the extra contrast as it was going to be a cloudy day with rain breaking out later on. Managed to shoot up the whole roll by driving ahead of the incoming weather, then got some shots of the back side of the storms later that evening. The camera performed very well, with good speeds, and the lens was nice and clear. I did have to clean out the view and rangefinder windows though before it could be used, but that is normal.
There will be some vignetting due to the Series IV hood I used (it came with the camera). Some creative cropping took care of most of it. I need to see if I have a wide-angle version.

Daybreak by P F McFarland, on Flickr

Tails by P F McFarland, on Flickr

Pontiac Chief by P F McFarland, on Flickr

Goodnight, Storm by P F McFarland, on Flickr
The culprit:

Kodak Series IV Hood by P F McFarland, on Flickr
See all the photos at https://flic.kr/s/aHsmCzDFpX
PF