# Convert date in the log file to a unix timestamp
to_unix_date() {
    date=$(awk '{print $4}' | sed "s/\[\([0-9][0-9]\)\/\([A-Z][a-z][a-z]\)\/\([0-9][0-9][0-9][0-9]\):\([0-9][0-9]\):\([0-9][0-9]\):\([0-9][0-9]\)/\1 \2 \3 \4:\5:\6/g")
    date --date="$date" "+%s"
}