Devil's Advocate

а ты про таймстампы?

Reference Timestamp
Local time at which the local clock was last set or corrected.

Originate Timestamp
Local time at which the request departed the client host for the service host.

Receive Timestamp
Local time at which the request arrived at the service host.

Transmit Timestamp
Local time at which the reply departed the service host for the client host.

[root@leskov a48]# ntpdate com
14 Mar 20:19:02 ntpdate[94193]: adjust time server 82.138.2.33 offset 0.150428 sec

[root@leskov a48]# tcpdump -i fxp0 -s 0 -X -vvv src or dst host com
tcpdump: listening on fxp0
20:19:02.525232 82.138.2.34.ntp > 82.138.2.33.ntp: [udp sum ok] v4 client strat 0 poll 4 prec -6 dist 1.000000 disp 1.000000 ref (unspec)@0.000000000 orig 0.000000000 rec -0.000000000 xmt -975157753.474839985 (ttl 64, id 10724, len 76)
0x0000 4500 004c 29e4 0000 4011 a766 528a 0222 E..L)...@..fR.."
0x0010 528a 0221 007b 007b 0038 f81a e300 04fa R..!.{.{.8......
0x0020 0001 0000 0001 0000 0000 0000 0000 0000 ................
0x0030 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0040 0000 0000 c5e0 4606 8670 e2c1 ......F..p..
20:19:02.527039 82.138.2.33.ntp > 82.138.2.34.ntp: [udp sum ok] v4 server strat 3 poll 4 prec -18 dist 0.084365 disp 0.029327 ref gw-sovam.gamma.ru@3319809513.161149799 orig 3319809542.525160014 rec +0.151343226 xmt +0.151408910 [tos 0xc0] (ttl 255, id 0, len 76)

[root@leskov a48]# perl -e '($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(3319809542-2208988800); print $year+1900, "/", $mon, "/", $mday, " ", $hour, ":", $min, ":", $sec, "\n";'
2005/2/14 20:19:2