That's gold.

That hardware real time clocks keep time in date and time drives me batty. And no one does the right thing which is just a 64 bit counter counting 32khz ticks. Then use canned tested code to convert that to butt scratching monkey time.

Story my old boss designed an STD Bus RTC card in 1978 or something. Kept time in YY:MM:DD HH:MM:SS 1/60 sec. And was battery backed. With shadow registers that latched the time. Couple of years later redesigned it as a 32 bit seconds counter. With a 32khz sub seconds counter. Plus a 48 bit offset register. What was a whole card was now a couple of 4000 series IC's on the processor card. He wrote 400 bytes of Z80 assembly to convert that to date and time. He said was tricky to get right but once done was done.

I would guess that’s because those chips were designed for use in systems that didn’t have a CPU, but reading the data sheet, it doesn’t look as if you can easily hook up this thing to 7-segment LEDs, so maybe this is a matter of “this is how we always did it, and if it ain’t broke, don’t fix it”, and then ‘fix’ it, anyways?