TimeProtocol is a simple but complete implementation of RFC868. This should not be confused with Network Time Protocol (NTP) or Simple Network Time Protocol (SNTP) which are quite common and much more complicated. See http://tools.ietf.org/html/rfc868 for specifications.

TimeProtocol implements both TCP and UDP communication and was writen in GO.

DOCKER
------
Build and run with docker compose (maps host port 37 -> the container's
unprivileged internal port, so the container runs fully as a non-root user):

    docker compose up --build -d

Or manually:

    docker build -t timeprotocol .
    docker run -d -p 37:8037/tcp -p 37:8037/udp timeprotocol

The listen port inside the container can be changed via the
TIMEPROTOCOL_PORT environment variable (default 8037).

SECURITY NOTES
--------------
RFC 868 has no authentication and the server replies to any source address,
so it can be used as a (low-amplification) UDP reflector if exposed to the
open internet. If you publish this port publicly, restrict it with a
firewall to trusted networks rather than exposing it to 0.0.0.0 broadly.
The RFC 868 32-bit seconds-since-1900 timestamp also rolls over in February
2036 -- that is a limitation of the protocol itself, not this
implementation.