CPU utilization spike every night

You can check your daily jobs by looking at "crontab -l" and the contents of /etc/cron.daily. The CPU peak could also be caused by traffic processing. Do you also see spikes in SSL TPS, connection count or traffic throughput at that time?

I would recommend that you check the number of connections/HTTP Requests/Throughput around the time of the CPU spike. The graphs for any or all of these variables may show similar pattern. I have usually seen such increase in CPU because of automated backup of database or any other similar application level backup and because the F5 handles these connections via VS, you can see a bump in cpu utilization.

cron.daily is configured by /etc/anacrontab:

[root@f5-1:Active:In Sync] config  cat /etc/anacrontab
 /etc/anacrontab: configuration file for anacron

 See anacron(8) and anacrontab(5) for details.

SHELL=/bin/sh
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
 the maximal random delay added to the base delay of the jobs
RANDOM_DELAY=45
 the jobs will be started during the following hours only
START_HOURS_RANGE=3-22

period in days   delay in minutes   job-identifier   command
1       5       cron.daily              nice run-parts /etc/cron.daily
7       25      cron.weekly             nice run-parts /etc/cron.weekly
@monthly 45     cron.monthly            nice run-parts /etc/cron.monthly

There are interesting options like "START_HOURS_RANGE" or "RANDOM_DELAY". But my cron is not customized, so I suppose, that this is general behavior. Maybe someone else have noticed same behavior.