Daytime Protocol
also
- std-25
Extracted elements (8)
The Daytime Protocol is intended as a useful debugging and measurement tool. Its simplicity — sending human-readable date/time without regard to input — makes it easy to implement and use for basic network testing.
The Daytime Protocol is explicitly not intended for machine-readable time. For machine-usable time, implementers should use the Time Protocol (RFC 868) instead.
A TCP daytime server MUST listen for connections on TCP port 13 and send the current date and time upon each connection.
A UDP daytime server MUST listen for datagrams on UDP port 13 and respond to each with the current date and time.
The Daytime Protocol provides a TCP-based service on port 13. Upon connection, the server sends the current date and time as an ASCII character string and discards any received data, then closes the connection.
The Daytime Protocol provides a UDP-based service on port 13. When a datagram is received, the server replies with the current date and time as an ASCII character string; the content of the received datagram is ignored.
One popular syntax is 'Weekday, Month Day, Year Time-Zone' (e.g., 'Tuesday, February 22, 1982 17:37:43-PST'). Another popular syntax (used in SMTP) is 'dd mmm yy hh:mm:ss zzz' (e.g., '02 FEB 82 07:59:01 PST'). No single format is mandated.
The daytime response is an ASCII character string. It is recommended to be limited to ASCII printing characters, space, carriage return, and line feed, and should be just one line.