[jovdg]

Call it "epoch", like (ao.):

- https://man7.org/linux/man-pages/man7/deb-version.7.html - https://rpm-packaging-guide.github.io/#epoch

[teddyh]

More canonical version of that first link:

https://manpages.debian.org/buster/dpkg-dev/deb-version.7.en...

Or possibly this one: https://www.debian.org/doc/debian-policy/ch-controlfields.ht...