What is it?
Jans is an unusual NTP server: it can return the systemclock time (and just that) but it can also return blatantly incorrect time. It is an NTP test-tool.
This program can be used to:
return the real system clock time
return invalid time.
send 'kiss of death'-packets
debug an NTP-client
You might want to return invalid time when for example you've been in pool.ntp.org and left it and want users who still use your server to forcibly stop using your server.
more new types of time
can now respond to ntpq 'peers' requests
allows you to participate in lotteries from all over the world!