:epoch: [UNIX: prob. from astronomical timekeeping] n. The time
and date corresponding to 0 in an operating system's clock and
timestamp values. Under most UNIX versions the epoch is 00:00:00
GMT, January 1, 1970; under VMS, it's 00:00:00 of November 17, 1858
(base date of the U.S. Naval Observatory's ephemerides); on a
Macintosh, it's the midnight beginning January 1 1904. System time
is measured in seconds or {tick}s past the epoch. Weird
problems may ensue when the clock wraps around (see {wrap
around}), which is not necessarily a rare event; on systems
counting 10 ticks per second, a signed 32-bit count of ticks is
good only for 6.8 years. The 1-tick-per-second clock of UNIX is
good only until January 18, 2038, assuming at least some software
continues to consider it signed and that word lengths don't
increase by then. See also {wall time}.
-- The AI Hackers Dictionary
and date corresponding to 0 in an operating system's clock and
timestamp values. Under most UNIX versions the epoch is 00:00:00
GMT, January 1, 1970; under VMS, it's 00:00:00 of November 17, 1858
(base date of the U.S. Naval Observatory's ephemerides); on a
Macintosh, it's the midnight beginning January 1 1904. System time
is measured in seconds or {tick}s past the epoch. Weird
problems may ensue when the clock wraps around (see {wrap
around}), which is not necessarily a rare event; on systems
counting 10 ticks per second, a signed 32-bit count of ticks is
good only for 6.8 years. The 1-tick-per-second clock of UNIX is
good only until January 18, 2038, assuming at least some software
continues to consider it signed and that word lengths don't
increase by then. See also {wall time}.
-- The AI Hackers Dictionary
Related:
- epoch n.
[Unix: prob. from astronomical timekeeping] The
time and date corresponding to 0 in an operating system's clock and
timestamp values.
Under most Unix versions the epoch is 00:00:00 GMT, January 1, 1970... - The 1-tick-per-second clock of UNIX is good only until January 18, 2038, assuming word lengths don't increase by then.
- wall time: n. (also `wall clock time') 1. `Real world' time (what
the clock on the wall shows), as opposed to the system clock's idea
of time.
2. The real running time of a program, as opposed to the number of {tick}s required to execute it (on a timesharing system these always differ, as no one program gets all the ticks, and on multiprocessor systems with good thread support one may get more processor time than real time).... - jiffy n.
1. The duration of one tick of the system clock on
your computer (see tick).
Often one AC cycle time (1/60 second in the U.... - jiffy: n. 1. The duration of one tick of the system clock on the
computer (see {tick}).
Often one AC cycle time (1/60 second in the U.... - UNIX was half a billion (500000000) seconds old on
Tue Nov 5 00
53:20 1985 GMT (measuring since the time(2) epoch). -- Andy Tannenbaum... - UNIX will be half a billion (500000000) seconds old on
Tue Nov 5 00
53:20 1985 GMT (measuring since the time(2) epoch). -- Andy Tannenbaum... - wall time n.
(also `wall clock time') 1. `Real world'
time (what the clock on the wall shows), as opposed to the system
clock's idea of time.
2. The real running time of a program, as opposed to the number of ticks required to execute it (on a timesharing system these always differ, as no one program gets all the ticks, and on multiprocessor systems with good thread support one may get more processor time than real time)....
