Here's a portable version for those of us who do not use Bash: a=$(printf '\xb%-47.s' \ |nc -uw1 ntp.metas.ch 123 \ |exec xxd -s40 -l4 -p) b=$(printf

Here's a portable version for those of us who do not use Bash: a=$(printf '\xb%-47.s' \ |nc -uw1 ntp.metas.ch 123 \ |exec xxd -s40 -l4 -p) b=$(printf %d\\n 0x"$a") c=$((b-2208988800)) date -r$c There is a way to do the xxd step using original netcat. Included with nc was a short program called nc-data. It converts from btoa and atob for shoveling data to nc. Slower than xxd but still useful. It also shows octal, decimal and byte number. Another exercise might be a one-liner for the TAICLOCK protocol: http://cr.yp.to/proto/taiclock.txt http://cr.yp.to/proto/taiclock.txt (Alternative to SNTP with smaller packets and support for leap seconds.)