If webalizer statistics of your website are only showing the last 1 or two days instead of all days since the website has been created, you have to activate incremental processing in the webalizer configuration file (/etc/webalizer.conf or /etc/webalizer/webalizer.conf depending on the Linux distribution).
vi /etc/webalizer/webalizer.conf
Change the line:
# Incremental yes
to:
Incremental yes
