change letsencrypt certbot run time - cron

Question

I have setup certbot for letsencrypt key renewal. This works.
When i check my logs at /etc/log/letsencrypt i see it runs twice a day.
Somewhere around midnight and somewhere around noon.
I would like to run it only once a day somewhere in the early morning.
To get control over the running of certbot i removed all entries from my cronjobs. But unexpectedly it still runs.
So how is certbot started?
Extra info:
when i run a script to show all cronjobs i get this:
(script: How do I list all cron jobs for all users? )
mi h d m w user command
0 3 * * 1 root /usr/bin/rsnapshot weekly
0 */4 * * * root /usr/bin/rsnapshot hourly
16 10 * * * root test -x /etc/cron.daily/popularity-contest && /etc/cron.daily/popularity-contest --crond
25 6 * * * root /etc/cron.daily/apache2
25 6 * * * root /etc/cron.daily/apt-compat
25 6 * * * root /etc/cron.daily/aptitude
25 6 * * * root /etc/cron.daily/automysqlbackup
25 6 * * * root /etc/cron.daily/bsdmainutils
25 6 * * * root /etc/cron.daily/dpkg
25 6 * * * root /etc/cron.daily/exim4-base
25 6 * * * root /etc/cron.daily/logrotate
25 6 * * * root /etc/cron.daily/man-db
25 6 * * * root /etc/cron.daily/mlocate
25 6 * * * root /etc/cron.daily/ntp
25 6 * * * root /etc/cron.daily/passwd
25 6 * * * root /etc/cron.daily/popularity-contest
25 6 * * * root /etc/cron.daily/tomcat8
30 2 1 * * root /usr/bin/rsnapshot monthly
30 3 * * * root /usr/bin/rsnapshot daily
47 6 * * 7 root /etc/cron.weekly/man-db
the file from certbot i found was certbot in /etc/cron.d
it contained this line:
#0 4 * * * root test -x /usr/bin/certbot -a \! -d /run/systemd/system && perl -e 'sleep int(rand(3600))' && certbot -q renew
which i commented out (with the #).
my system is debian:
Debian GNU/Linux 9

Answer 1

I use certbot with Ubuntu 16.04 + nginx
There are two places to check jobs related to Certbot
1) /etc/cron.d/certbot
here you have
0 */12 * * * root test -x /usr/bin/certbot -a \! -d /run/systemd/system && perl -e 'sleep int(rand(3600))' && certbot -q renew && nginx -s reload
2) systemd timer
run commnad:
$sudo systemctl list-timers
and see output
Sun 2018-07-08 00:46:59 EEST 7h left Sat 2018-07-07 12:36:26 EEST 4h 51min ago certbot.timer certbot.service
then
3)
go to check file that control time when systemctl run Certbot
/etc/systemd/system/timers.target.wants/certbot.timer
that is symbolic link for
/lib/systemd/system/certbot.timer
Pay attention to this lines that define times + random seconds (set a random time for purpose to don't stress simultaneously letsencrypt servers)
OnCalendar=--* 00,12:00:00
RandomizedDelaySec=3600