First of all, you have to create a simple perl file with the following text:
=============================
#! /usr/bin/perl -p
s/^\d+\.\d+/localtime $&/e;
=============================
name the file as timeconvert.pl
Then from the command line, issue the following order:
cat /var/log/squid/access.log | /timeconvert.pl > /var/log/squid/access-01-24.log
This will convert the dates and creates a new file with the name access-01-24.log
Regards,
Samer Pharaon