After updating to Devuan 3 the date command shows 12hours am/pm but my days have 24 hours. The locale was always en_US.UTF8 to keep sane command and error output.
Debian 10 thinks they had to fix the correct hour display to the complicated one.
Therefor all sysadmins like me have to apply the following workaround, to keep both sane command output and reasonable time format.
This changed the locale for time output to “C” in /etc/default/locale. Date looks correct again:
# date Mon Jun 8 21:20:33 CEST 2020