Colin Perkins skrev:
On 10 Nov 2006, at 00:10, Alfred HÎnes wrote:(7) clarification The second paragraph of Section 5.9, on page 17, says: The first and second sub-fields give the start and stop times, respectively, for the session. These values are the decimal representation of Network Time Protocol (NTP) time values in seconds since 1900 [13]. To convert these values to UNIX time, subtract decimal 2208988800. To make the time base unique and absolute, the time zone (UTC) needs to be specified. Hence, the RFC should say: The first and second sub-fields give the start and stop times, respectively, for the session. These values are the decimal representation of Network Time Protocol (NTP) time values in seconds | since 1900, UTC [13]. To convert these values to UNIX time, subtract decimal 2208988800.Does anyone understand appendix E of RFC 1305 well enough to comment? I'm not sure this change is correct, but equally it's not clear that the current text is right either.http://ftp.arnes.si/standards/rfc/rfc1305.pdf starting on page 70 (you need the PDF version of this RFC...)
In reality this likely hasn't been a problem as both NTP and Unix time uses UTC as base, but to be clear adding that is probably fine.
What I really wonder is how correct the "To convert these ..." is due to the leap seconds. To my understanding Unix times uses a definition that a day always is 86400 seconds. While to my understanding the NTP timestamp will contain the leap seconds. And if NTP timestamps are to be converted into UTC time year, day, hour and second then they need to be taken into account. Thus a simple subtraction will be giving the wrong time.
Cheers Magnus Westerlund IETF Transport Area Director & TSVWG Chair ---------------------------------------------------------------------- Multimedia Technologies, Ericsson Research EAB/TVM ---------------------------------------------------------------------- Ericsson AB | Phone +46 8 4048287 Färögatan 6 | Fax +46 8 7575550 S-164 80 Stockholm, Sweden | mailto: magnus.westerlund at ericsson.com ---------------------------------------------------------------------- _______________________________________________ mmusic mailing list mmusic at ietf.org https://www.ietf.org/mailman/listinfo/mmusic