Information Technology Reference
In-Depth Information
the.basis.of.how.many.100.nanosecond.periods.have.passed.
since. January. 1,. 1601,. while. UNIX. systems. track. seconds.
since.January.1,.1970.
These. are. arbitrary. choices. made. by. geeks. with. not.
enough.to.keep.them.challenged.in.my.humble.opinion,.but.
in.any.case.that.is.how.these.operating.systems.keep.track.
of.the.time.and.record.it.internally..However,.as.with.every-
thing.in.our.electronic.world,.those.geeks.knew.better.than.to.
expect.us.normal.humans.to.be.able.to.decode.their.schemes..
All. modern. electronic. devices. decode. and. represent. these.
system.time.data.to.users.as.a.time.and.date.we.recognize,.
such. as. October. 15,. 1978,. at. 12:01:06:13. which. actually.
does.take.us.down.to.the.millisecond.level.if.we.care.to.know.
it.(in.this.case.06.is.the.hundredths.of.seconds.and.13.is.the.
milliseconds)..But.the.important.thing.to.understand.is.where.
the.computer.gets.that.time.from.in.the.irst.place..Does.it.
come.out.of.midair?.I.guess.in.some.cases.you.might.say.that.
it.does.
The.bottom.line.is.that.the.time.a.computer.records.and.
stores. is. entirely. dependent. on. input. it. gets. from. outside..
There.is.no.magic.time.inder.hiding.inside.of.each.computer.
Computers. and. all. of. the. devices. that. use. computing.
systems. (phones,. cameras,. toasters,. VCRs,. televisions,.
etc.). will. contain. a. chip. that. keeps. track. of. milliseconds.
and. in. many. cases. will. have. a. backup. battery. that. keeps.
it.running.so.it.does.not.lose.track.when.you.turn.off.the.
power..Some.of.these.devices,.as.noted.above,.will.get.their.
information.out.of.midair.by.picking.up.radio.signals.from.
the. atomic. clock. at. the. U.S.. Naval. Observatory. or. other.
sources..These.are.accepted.standard.keepers.for.the.“real”.
time.worldwide.
Other. devices. get. their. time. reference. from. a. network.
time.server.that.they.are.connected.to.via.a.wired.or.wireless.
network..That.server.has.in.turn.gotten.its.time.from.some.
other.source,.perhaps.the.atomic.clocks.noted.above.
Because. this. is. so. important. to. the. smooth. running. of.
our.society,.standards.have.been.established.and.are.adhered.
