I set some jobs via crontab -e. For instance, I use it to run my tv recorder script an also to turn off computer at night.
Inside /etc, I found different types of cron directories (cron.hourly; cron.weekly and cron.monthly). Cron.hourly is empty but the rest contain a file called 0anacron and if I open it, it looks like this (the only thing changing is that instead of cron.daily, the script uses cron.weekly or cron.monthly depending if the are inside cron.daily; cron.weekly or cron.monthly):
# anacron's cron script
# This script updates anacron time stamps. It is called through run-parts
# either by anacron itself or by cron.
# The script is called "0anacron" to assure that it will be executed
# _before_ all other scripts.
test -x /usr/sbin/anacron || exit 0
anacron -u cron.daily
Are these scripts necessary to use cron? What happens if I comment those two lines inside the script? Will anything change? What do they do?
I will really appreciate your replies and explanation.