AFAIK, uname -v and /proc/version shall give the compile time of the kernel. Am I right? It now gives times close to last git check-in time.
The goal is to be able to compile identical "reproducible" binaries later, so the file times are adjusted in a definite way (to the time of the last git commit). Likely also the kernel version time is set the same way.
Most likely the behaviour is due to
and uses the time set by
In my own personal build I want the date/time to be the actual compile time, so I override the default SOURCE_DATE_EPOCH logic by setting the current date/time to a file "version.date" in the buildroot root dir before running "make".
# Override git/svn timestamp after r48583-48594, set initial clock to now date +%s > version.date
Now that you mention this, I recall a presentation in FOSDEM 2016 about
that topic. I just didn't realized that this was already happened.