Simple function to convert timestamp or timeuuid to human readable date

epoch.sh

#!/bin/bash
function epoch() {
    number='^[0-9]{13}$'
    uuid='^[0-9a-fA-F]{8}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{12}$'
    if [[ "$1" =~ $number ]]; then
        TS=$1
    elif [[ "$1" =~ $uuid ]]; then
        strdate="$(uuid -d $1 | grep 'time:' | awk '{print $3,$4}' | cut -c1-26)"
        TS=$(($(date -d "$strdate" +"%s%N") / 1000000))
    else 
        echo "Invalid parameter will print now"
        TS="$(date +%s%N | cut -b1-13)"
    fi
    s=${TS%???}
    ms=${TS#"$s"}
    echo "millis: $TS - $(date -d @$s +"%F %T.$ms UTC")"
}