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			252 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
| <HTML><HEAD><TITLE>Tcl Built-In Commands - clock manual page</TITLE></HEAD><BODY>
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| <DL>
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| <DD><A HREF="clock.htm#M2" NAME="L109">NAME</A>
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| <DL><DD>clock - Obtain and manipulate time</DL>
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| <DD><A HREF="clock.htm#M3" NAME="L110">SYNOPSIS</A>
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| <DL>
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| <DD><B>clock </B><I>option</I> ?<I>arg arg ...</I>?
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| </DL>
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| <DD><A HREF="clock.htm#M4" NAME="L111">DESCRIPTION</A>
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| <DL>
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| <DD><A HREF="clock.htm#M5" NAME="L112">.VS 8.3</A>
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| <DD><A HREF="clock.htm#M6" NAME="L113"><B>clock format </B><I>clockValue</I> ?<B>-format </B><I>string</I>? ?<B>-gmt </B><I>boolean</I>?</A>
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| <DL>
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| <DD><A HREF="clock.htm#M7" NAME="L114"><B>%%</B></A>
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| <DD><A HREF="clock.htm#M8" NAME="L115"><B>%a</B></A>
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| <DD><A HREF="clock.htm#M9" NAME="L116"><B>%A</B></A>
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| <DD><A HREF="clock.htm#M10" NAME="L117"><B>%b</B></A>
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| <DD><A HREF="clock.htm#M11" NAME="L118"><B>%B</B></A>
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| <DD><A HREF="clock.htm#M12" NAME="L119"><B>%c</B></A>
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| <DD><A HREF="clock.htm#M13" NAME="L120"><B>%d</B></A>
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| <DD><A HREF="clock.htm#M14" NAME="L121"><B>%H</B></A>
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| <DD><A HREF="clock.htm#M15" NAME="L122"><B>%I</B></A>
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| <DD><A HREF="clock.htm#M16" NAME="L123"><B>%j</B></A>
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| <DD><A HREF="clock.htm#M17" NAME="L124"><B>%m</B></A>
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| <DD><A HREF="clock.htm#M18" NAME="L125"><B>%M</B></A>
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| <DD><A HREF="clock.htm#M19" NAME="L126"><B>%p</B></A>
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| <DD><A HREF="clock.htm#M20" NAME="L127"><B>%S</B></A>
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| <DD><A HREF="clock.htm#M21" NAME="L128"><B>%U</B></A>
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| <DD><A HREF="clock.htm#M22" NAME="L129"><B>%w</B></A>
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| <DD><A HREF="clock.htm#M23" NAME="L130"><B>%W</B></A>
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| <DD><A HREF="clock.htm#M24" NAME="L131"><B>%x</B></A>
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| <DD><A HREF="clock.htm#M25" NAME="L132"><B>%X</B></A>
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| <DD><A HREF="clock.htm#M26" NAME="L133"><B>%y</B></A>
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| <DD><A HREF="clock.htm#M27" NAME="L134"><B>%Y</B></A>
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| <DD><A HREF="clock.htm#M28" NAME="L135"><B>%Z</B></A>
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| </DL>
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| <DL>
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| <DD><A HREF="clock.htm#M29" NAME="L136"><B>%D</B></A>
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| <DD><A HREF="clock.htm#M30" NAME="L137"><B>%e</B></A>
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| <DD><A HREF="clock.htm#M31" NAME="L138"><B>%h</B></A>
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| <DD><A HREF="clock.htm#M32" NAME="L139"><B>%n</B></A>
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| <DD><A HREF="clock.htm#M33" NAME="L140"><B>%r</B></A>
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| <DD><A HREF="clock.htm#M34" NAME="L141"><B>%R</B></A>
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| <DD><A HREF="clock.htm#M35" NAME="L142"><B>%t</B></A>
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| <DD><A HREF="clock.htm#M36" NAME="L143"><B>%T</B></A>
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| </DL>
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| <DD><A HREF="clock.htm#M37" NAME="L144"><B>clock scan </B><I>dateString</I> ?<B>-base </B><I>clockVal</I>? ?<B>-gmt </B><I>boolean</I>?</A>
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| <DL>
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| <DD><A HREF="clock.htm#M38" NAME="L145"><I>time</I></A>
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| <DD><A HREF="clock.htm#M39" NAME="L146"><I>date</I></A>
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| <DD><A HREF="clock.htm#M40" NAME="L147"><I>ISO 8601 point-in-time</I></A>
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| <DD><A HREF="clock.htm#M41" NAME="L148"><I>relative time</I></A>
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| </DL>
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| <DD><A HREF="clock.htm#M42" NAME="L149"><B>clock seconds</B></A>
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| </DL>
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| <DD><A HREF="clock.htm#M43" NAME="L150">KEYWORDS</A>
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| </DL><HR>
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| <H3><A NAME="M2">NAME</A></H3>
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| clock - Obtain and manipulate time
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| <H3><A NAME="M3">SYNOPSIS</A></H3>
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| <B>clock </B><I>option</I> ?<I>arg arg ...</I>?<BR>
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| <H3><A NAME="M4">DESCRIPTION</A></H3>
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| This command performs one of several operations that may obtain
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| or manipulate strings or values that represent some notion of
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| time.  The <I>option</I> argument determines what action is carried
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| out by the command.  The legal <I>options</I> (which may be
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| abbreviated) are:
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| <P>
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| <DL>
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| <P><DT><A NAME="M5">.VS 8.3</A><DD>
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| <B>clock clicks</B> ?<B>-milliseconds</B>?
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| Return a high-resolution time value as a system-dependent integer
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| value.  The unit of the value is system-dependent but should be the
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| highest resolution clock available on the system such as a CPU cycle
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| counter. If <B>-milliseconds</B> is specified, then the value is
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| guaranteed to be of millisecond granularity.
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| This value should only be used for the relative measurement
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| of elapsed time.
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| <P><DT><A NAME="M6"><B>clock format </B><I>clockValue</I> ?<B>-format </B><I>string</I>? ?<B>-gmt </B><I>boolean</I>?</A><DD>
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| Converts an integer time value, typically returned by
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| <B>clock seconds</B>, <B>clock scan</B>, or the <B>atime</B>, <B>mtime</B>,
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| or <B>ctime</B> options of the <B><A HREF="../TkCmd/file.htm">file</A></B> command, to human-readable
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| form.  If the <B>-format</B> argument is present the next argument is a
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| string that describes how the date and time are to be formatted.
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| Field descriptors consist of a <B>%</B> followed by a field
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| descriptor character.  All other characters are copied into the result.
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| Valid field descriptors are:
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| <P>
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| <DL>
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| <P><DT><A NAME="M7"><B>%%</B></A><DD>
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| Insert a %.
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| <P><DT><A NAME="M8"><B>%a</B></A><DD>
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| Abbreviated weekday name (Mon, Tue, etc.).
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| <P><DT><A NAME="M9"><B>%A</B></A><DD>
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| Full weekday name (Monday, Tuesday, etc.).
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| <P><DT><A NAME="M10"><B>%b</B></A><DD>
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| Abbreviated month name (Jan, Feb, etc.).
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| <P><DT><A NAME="M11"><B>%B</B></A><DD>
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| Full month name.
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| <P><DT><A NAME="M12"><B>%c</B></A><DD>
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| Locale specific date and time.
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| <P><DT><A NAME="M13"><B>%d</B></A><DD>
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| Day of month (01 - 31).
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| <P><DT><A NAME="M14"><B>%H</B></A><DD>
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| Hour in 24-hour format (00 - 23).
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| <P><DT><A NAME="M15"><B>%I</B></A><DD>
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| Hour in 12-hour format (00 - 12).
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| <P><DT><A NAME="M16"><B>%j</B></A><DD>
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| Day of year (001 - 366).
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| <P><DT><A NAME="M17"><B>%m</B></A><DD>
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| Month number (01 - 12).
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| <P><DT><A NAME="M18"><B>%M</B></A><DD>
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| Minute (00 - 59).
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| <P><DT><A NAME="M19"><B>%p</B></A><DD>
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| AM/PM indicator.
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| <P><DT><A NAME="M20"><B>%S</B></A><DD>
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| Seconds (00 - 59).
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| <P><DT><A NAME="M21"><B>%U</B></A><DD>
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| Week of year (00 - 52), Sunday is the first day of the week.
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| <P><DT><A NAME="M22"><B>%w</B></A><DD>
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| Weekday number (Sunday = 0).
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| <P><DT><A NAME="M23"><B>%W</B></A><DD>
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| Week of year (00 - 52), Monday is the first day of the week.
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| <P><DT><A NAME="M24"><B>%x</B></A><DD>
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| Locale specific date format.
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| <P><DT><A NAME="M25"><B>%X</B></A><DD>
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| Locale specific time format.
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| <P><DT><A NAME="M26"><B>%y</B></A><DD>
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| Year without century (00 - 99).
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| <P><DT><A NAME="M27"><B>%Y</B></A><DD>
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| Year with century (e.g. 1990)
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| <P><DT><A NAME="M28"><B>%Z</B></A><DD>
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| Time zone name.
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| <P></DL>
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| <P>
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| <DL><P><DD>
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| In addition, the following field descriptors may be supported on some
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| systems (e.g. Unix but not Windows):
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| <P>
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| <DL>
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| <P><DT><A NAME="M29"><B>%D</B></A><DD>
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| Date as %m/%d/%y.
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| <P><DT><A NAME="M30"><B>%e</B></A><DD>
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| Day of month (1 - 31), no leading zeros.
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| <P><DT><A NAME="M31"><B>%h</B></A><DD>
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| Abbreviated month name.
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| <P><DT><A NAME="M32"><B>%n</B></A><DD>
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| Insert a newline.
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| <P><DT><A NAME="M33"><B>%r</B></A><DD>
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| Time as %I:%M:%S %p.
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| <P><DT><A NAME="M34"><B>%R</B></A><DD>
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| Time as %H:%M.
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| <P><DT><A NAME="M35"><B>%t</B></A><DD>
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| Insert a tab.
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| <P><DT><A NAME="M36"><B>%T</B></A><DD>
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| Time as %H:%M:%S.
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| <P></DL>
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| </DL>
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| <P>
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| <DL><P><DD>
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| If the <B>-format</B> argument is not specified, the format string 
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| "<B>%a %b %d %H:%M:%S %Z %Y</B>" is used.  If the <B>-gmt</B> argument
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| is present the next argument must be a boolean which if true specifies
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| that the time will be formatted as Greenwich Mean Time. If false
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| then the local timezone will be used as defined by the operating
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| environment.
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| </DL>
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| <P><DT><A NAME="M37"><B>clock scan </B><I>dateString</I> ?<B>-base </B><I>clockVal</I>? ?<B>-gmt </B><I>boolean</I>?</A><DD>
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| Convert <I>dateString</I> to an integer clock value (see <B>clock seconds</B>).
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| This command can parse and convert virtually any standard date and/or time
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| string, which can include standard time zone mnemonics.  If only a time is
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| specified, the current date is assumed.  If the string does not contain a
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| time zone mnemonic, the local time zone is assumed, unless the <B>-gmt</B> 
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| argument is true, in which case the clock value is calculated assuming
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| that the specified time is relative to Greenwich Mean Time.
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| <B>-gmt</B>, if specified, affects only the computed time value; it does not
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| impact the interpretation of <B>-base</B>.
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| <P>
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| If the <B>-base</B> flag is specified, the next argument should contain
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| an integer clock value.  Only the date in this value is used, not the
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| time.  This is useful for determining the time on a specific day or
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| doing other date-relative conversions.
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| <P>
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| The <I>dateString</I> consists of zero or more specifications of the
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| following form:
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| <P>
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| <DL>
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| <P><DT><A NAME="M38"><I>time</I></A><DD>
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| A time of day, which is of the form: <I>hh</I>?<I>:mm</I>?<I>:ss</I>?? 
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| ?<I>meridian</I>? ?<I>zone</I>? or <I>hhmm </I>?<I>meridian</I>? 
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| ?<I>zone</I>?. If no meridian is specified, <I>hh</I> is interpreted on
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| a 24-hour clock.
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| <P><DT><A NAME="M39"><I>date</I></A><DD>
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| A specific month and day with optional year.  The
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| acceptable formats are <I>mm/dd</I>?<I>/yy</I>?, <I>monthname dd</I>
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| ?, <I>yy</I>?, <I>dd monthname </I>?<I>yy</I>?, <I>day, dd monthname
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| yy</I>, <I>?CC?yymmdd</I>, <I>?CC?yy-mm-dd</I>, <I>dd-monthname-?CC?yy</I>.
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| The default year is the current year.  If the year is less
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| than 100, we treat the years 00-68 as 2000-2068 and the years 69-99
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| as 1969-1999.  Not all platforms can represent the years 38-70, so
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| an error may result if these years are used.
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| <P><DT><A NAME="M40"><I>ISO 8601 point-in-time</I></A><DD>
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| An ISO 8601 point-in-time specification, such as <I>CCyymmddThhmmss</I>, where
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| T is the literal T, <I>CCyymmdd hhmmss</I>, or 
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| <I>CCyymmddThh:mm:ss</I>.
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| <P><DT><A NAME="M41"><I>relative time</I></A><DD>
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| A specification relative to the current time.  The format is <I>number
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| unit</I> acceptable units are <B>year</B>, <B>fortnight</B>, <B>month</B>, <B>week</B>, <B>day</B>,
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| <B>hour</B>, <B>minute</B> (or <B>min</B>), and <B>second</B> (or <B>sec</B>).  The
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| unit can be specified as a singular or plural, as in <B>3 weeks</B>.
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| These modifiers may also be specified:
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| <B>tomorrow</B>, <B>yesterday</B>, <B>today</B>, <B>now</B>,
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| <B>last</B>, <B>this</B>, <B>next</B>, <B>ago</B>.
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| <P></DL>
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| <P>
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| <DL><P><DD>
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| The actual date is calculated according to the following steps.
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| First, any absolute date and/or time is processed and converted.
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| Using that time as the base, day-of-week specifications are added.
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| Next, relative specifications are used.  If a date or day is
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| specified, and no absolute or relative time is given, midnight is
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| used.  Finally, a correction is applied so that the correct hour of
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| the day is produced after allowing for daylight savings time
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| differences and the correct date is given when going from the end
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| of a long month to a short month.
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| <P>
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| Daylight savings time correction is applied only when the relative time
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| is specified in units of days or more, ie, days, weeks, fortnights, months or
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| years.  This means that when crossing the daylight savings time boundary,
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| different results will be given for <B>clock scan "1 day"</B> and
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| <B>clock scan "24 hours"</B>:
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| <PRE><B>% clock scan "1 day" -base [clock scan 1999-10-31]
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| 941443200
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| % clock scan "24 hours" -base [clock scan 1999-10-31]
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| 941439600</B></PRE>
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| </DL>
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| <P><DT><A NAME="M42"><B>clock seconds</B></A><DD>
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| Return the current date and time as a system-dependent integer value.  The
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| unit of the value is seconds, allowing it to be used for relative time
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| calculations.  The value is usually defined as total elapsed time from
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| an ``epoch''.  You shouldn't assume the value of the epoch.
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| 
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| <P></DL>
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| <H3><A NAME="M43">KEYWORDS</A></H3>
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| <A href="../Keywords/C.htm#clock">clock</A>, <A href="../Keywords/D.htm#date">date</A>, <A href="../Keywords/T.htm#time">time</A>
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| <HR><PRE>
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| <A HREF="../copyright.htm">Copyright</A> © 1992-1995 Karl Lehenbauer and Mark Diekhans.
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| <A HREF="../copyright.htm">Copyright</A> © 1995-1997 Sun Microsystems, Inc.
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| <A HREF="../copyright.htm">Copyright</A> © 1998-1999 Scriptics Corporation
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| <A HREF="../copyright.htm">Copyright</A> © 1995-1997 Roger E. Critchlow Jr.</PRE>
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| </BODY></HTML>
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