<s>
timed	B-Protocol
(	O
time	O
daemon	B-Operating_System
)	O
is	O
an	O
operating	B-Operating_System
system	I-Operating_System
program	I-Operating_System
that	O
maintains	O
the	O
system	B-Operating_System
time	I-Operating_System
in	O
synchronization	O
with	O
time	O
servers	O
using	O
the	O
Time	O
Synchronization	O
Protocol	O
(	O
TSP	O
)	O
developed	O
by	O
Riccardo	O
Gusella	O
and	O
Stefano	O
Zatti	O
.	O
</s>
<s>
With	O
the	O
release	O
of	O
macOS	B-Operating_System
High	I-Operating_System
Sierra	I-Operating_System
in	O
2017	O
,	O
timed	B-Protocol
in	O
macOS	B-Application
has	O
subsumed	O
all	O
time	O
synchronization	O
responsibilities	O
including	O
those	O
of	O
the	O
former	O
ntpd	B-Protocol
and	O
timed	B-Protocol
.	O
</s>
