Here is an example of what is logged in the date time field of my Squid Access log. (access.log)
Know the date and time of the log run the below mentioned commend on
access.log file, it will display the date and time of the log recorded.
perl -pe 's/\d+/localtime($&)/e' access.log
You can export the converted display on your screen to a file also by running below mentioned commend
perl -pe 's/\d+/localtime($&)/e' access.log > convertedlog.txt