To summarize what we discovered in the comments:
At some point (before the upgrade), /etc/login.conf was populated with
:lang=de_DE.UTF-8 in the default class. After updating to FreeBSD 10.2, cron was presumably restarted, and picked up the new locale. The new locale caused the date formats inside the setuid.today file to change.
The FreeBSD 10.2 Release Notes don't mention changes to /etc/login.conf (closest is the Inconsistency between locale and rune locale states patch, but it does not appear to touch /etc/login.conf).
The solution is to change the default locale back and use ~/.login_conf overrides where a different locale is desired; then restart cron.