Symmetricom Time Server user manual Time and Daytime Protocols, Time Protocol as per RFC-868

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TIME and DAYTIME Protocols

C.1 TIME Protocol as per RFC-868

TIME protocol provides a site-independent, machine readable date and time. The TIME service sends back to the originating source the UTC time in seconds since midnight on January 1, 1900.

This protocol may be used either above the Transmission Control Protocol (TCP) or above the User Datagram Protocol (UDP).

When used via UDP, the TIME service works as follows: Server:Listen on port 37 (45 octal).

Client:Send an empty datagram to port 37.

Server:Send a datagram containing the UTC time as a 32 bit binary number. Client:Receive the TIME datagram.

The server listens for a datagram on port 37. When a datagram arrives, the server returns a datagram containing the 32-bit time value. If the server is unable to determine the time at its site, it should discard the arriving datagram and make no reply.

C.1.1 The Time Protocol Format

The time is the number of seconds since 00:00 (midnight) 1 January 1900 UTC, such that the time 1 is 12:00:01 AM on January 1, 1900 UTC; this base will serve until the year 2036.

6000-100AppC.fm Rev. D TimeVault™ User’s Manual C-105