Just did a fresh install of PVE. Going over the stock cron jobs I found this:
In /etc/cron.d/zfsutils-linux
# TRIM the first Sunday of every month.
24 0 1-7 * * root if [ $(date +\%w) -eq 0 ] && [ -x /usr/lib/zfs-linux/trim ]; then /usr/lib/zfs-linux/trim; fi
Actually works out to the...