show time from Internetz in shell, iso-8601

time-from-internet.sh

curl -G -s --data-urlencode "format=%FT%T%:z" http://www.timeapi.org/cet/now  # www.timeapi.org cet is CET/CEST. Don't use cest
date --iso-8601='seconds' -d "$(curl -s http://www.timeapi.org/utc/now)"      # www.timeapi.org use local timezone settings
date -d "$(curl -s http://www.timeapi.org/utc/now)" +"%FT%T (UTC%:z = %Z)"    # not quite ISO with timezone illustration
date -d "$(curl -s http://www.timeapi.org/utc/now)" +"%A %d.%m.%Y, %T (UTC%:z = %Z)" # non-ISO, easy readable by a german with day of week

date --iso-8601='seconds' -d "$(curl -s --head http://google.com | grep ^Date: | sed 's/Date: //g')" # google.com

date --iso-8601='seconds' -d "$(cat </dev/tcp/time.nist.gov/13 | cut -d' ' -f2,3) UTC" # NIST

 date --iso-8601='seconds' -d "$(cat </dev/tcp/de.pool.ntp.org/13)" # ntp pool project