<s>
The	O
Time	B-Protocol
Protocol	I-Protocol
is	O
a	O
network	O
protocol	O
in	O
the	O
Internet	B-Protocol
Protocol	I-Protocol
Suite	I-Protocol
defined	O
in	O
1983	O
in	O
RFC	O
868	O
by	O
Jon	O
Postel	O
and	O
K	O
.	O
Harrenstein	O
.	O
</s>
<s>
The	O
Time	B-Protocol
Protocol	I-Protocol
may	O
be	O
implemented	O
over	O
the	O
Transmission	B-Protocol
Control	I-Protocol
Protocol	I-Protocol
(	O
TCP	O
)	O
or	O
the	O
User	B-Protocol
Datagram	I-Protocol
Protocol	I-Protocol
(	O
UDP	O
)	O
.	O
</s>
<s>
A	O
host	O
connects	O
to	O
a	O
server	O
that	O
supports	O
the	O
Time	B-Protocol
Protocol	I-Protocol
on	O
port	O
37	O
.	O
</s>
<s>
Programs	O
that	O
use	O
the	O
Time	B-Protocol
Protocol	I-Protocol
must	O
be	O
carefully	O
designed	O
to	O
use	O
context-dependent	O
information	O
to	O
distinguish	O
these	O
dates	O
from	O
those	O
in	O
1900	O
.	O
</s>
<s>
Many	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
used	O
the	O
Time	B-Protocol
Protocol	I-Protocol
to	O
monitor	O
or	O
synchronize	O
their	O
clocks	O
using	O
the	O
rdate	B-Protocol
utility	O
,	O
but	O
this	O
function	O
was	O
superseded	O
by	O
the	O
Network	B-Protocol
Time	I-Protocol
Protocol	I-Protocol
(	O
NTP	O
)	O
and	O
the	O
corresponding	O
ntpdate	B-Protocol
utility	O
.	O
</s>
<s>
On	O
most	O
UNIX-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
a	O
Time	B-Protocol
Protocol	I-Protocol
server	O
is	O
built	O
into	O
the	O
inetd	B-Protocol
(	O
or	O
xinetd	B-Operating_System
)	O
daemon	B-Operating_System
.	O
</s>
