174 lines
2.8 KiB
HTML
174 lines
2.8 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<HTML
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><HEAD
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><TITLE
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>Computer Global Date and Time Concept</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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REL="HOME"
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TITLE="Managing Accurate Date and Time"
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HREF="index.html"><LINK
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REL="PREVIOUS"
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TITLE="Why do We Need a Precise Clock?"
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HREF="why.html"><LINK
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REL="NEXT"
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TITLE="What are Time Zones?"
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HREF="tz.html"></HEAD
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><BODY
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COLSPAN="3"
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>Managing Accurate Date and Time</TH
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></TR
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><TR
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WIDTH="10%"
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><DIV
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CLASS="section"
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><H1
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CLASS="section"
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><A
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NAME="time"
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></A
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>2. Computer Global Date and Time Concept</H1
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><P
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>To determine the current time for some planet region, a computer needs exactly this two informations:</P
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><P
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></P
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><OL
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TYPE="1"
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><LI
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><P
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>Correct <SPAN
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CLASS="acronym"
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>UTC</SPAN
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> (universal time as in Greenwich, but not <SPAN
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CLASS="acronym"
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>GMT</SPAN
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>) time</P
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></LI
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><LI
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><P
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>Region's current Time Zone</P
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></LI
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></OL
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><P
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>For computers, there is also the hardware clock, which is used as a base by the OS to set its time.</P
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><P
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>OS date and time (we'll use only date <EM
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>or</EM
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> time from now on) is set on boot, by some script that reads the hardware clock, makes Time Zone calculations (there is no time zone data stored in <SPAN
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CLASS="acronym"
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>BIOS</SPAN
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>) and sets the OS. After this synchronization, <SPAN
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CLASS="acronym"
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>BIOS</SPAN
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> and OS time are independent from each other. So after a while they may have some seconds of difference. Which one is correct? If you don't make special configurations, none of them.</P
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><P
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>We'll discuss here how to make them both <EM
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>globally 100% accurate</EM
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>.</P
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HREF="why.html"
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>Prev</A
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>Home</A
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HREF="tz.html"
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>Next</A
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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>Why do We Need a Precise Clock?</TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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> </TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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>What are Time Zones?</TD
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></TR
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></DIV
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></BODY
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> |