You mentioned Bosch and I can't think of anywhere or anyone else who'd be interested in this little bit of trivia, so a random comment on a thread about filing the edges off a laptop seems like a fitting place to share it.

Bosch dates their appliances using a thing called the Fertigungsdatum Number. The first two digits represent the year of manufacture, the second two are for the month. Except the year doesn't align with the actual year, you first have to add 20. Why 20? Well, Bosch first started using their internal dating system back in 1920 and appliances from that year started with the code "00". I had an oven that had a date of "7808", which means it was manufactured in August 1998 (it lasted almost 30 years before we finally had to replace it last month).

In 2020 the system wound back around and started with "00" again.