Just dropping this here:

https://gist.github.com/Cybso/77b8f7bdec78e0a8df8f8435e3ccb8fc

# Sorts the rows of one or multiple apache access_log files

# by date (ascending) and converts them from 'common' log format
# into 'combined' (if you switched the log file format meanwhile).
#
# This is useful when you want to merge multiple log files, e.g. when
# you have different files for HTTP and HTTPS.
#
# Usage:
#     sort-access-log [file [file...]]
#
# If the argument ends on .gz it will be extracted using 'gunzip'.
# If no argument has been given the script expects the input on STDIN.
#
# The date is expected to have the following format, which must occur
# *anywhere* within the line:
#
#    [20/Mar/2017:12:00:37 +0100]
#
# The timezone argument is ignored, so this might be inaccurate when
# changing from summer time to winter time - for me this doesn't matter.
#
# The output of the program can be used as input for awffull or
# webalizer.