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STARDATE(1)		     General Commands Manual		     STARDATE(1)

NAME
     stardate - convert between stardates and other calendars

SYNOPSIS
     stardate [ options ] [ date ... ]

DESCRIPTION
     stardate  interprets  the	dates specified on its command line, and outputs
     them in the formats specified by the options.

     If no dates are specified, the current time, read from the system clock, is
     used.  If no options are specified, dates are output in the form  of  star-
     dates.   Consequently, if stardate is invoked with no arguments, it outputs
     the current time as a  stardate.	This  performs	much  the  same  job  as
     date(1), but with a more interesting form of output.

     Dates on output are always rounded down, and so in some cases will generate
     different output if reused as input.  This rounding is always such that the
     output  date is the latest time, expressible in the format being used, that
     is no later than the time specified as input.

     This program handles dates from 0001=01=01 (Julian calendar)  up  to  (cur-
     rently)  (2^64  -	1)  seconds later, which is beyond the year (5 x 10^11).
     Any date within this range can be input or output in any of the formats the
     program supports.	Consequently, any date the program outputs will  be  ac-
     cepted  as  input.   The  only exception is for dates within the first half
     second of the acceptable range, where the value output in the quadcent cal-
     endar,  ``0000*12*31T02:03:16''  (chosen  due  to	the  rounding  mentioned
     above), is actually outside the acceptable range.

     The  stardate code is based on information in version 1 of the Stardates in
     Star  Trek  FAQ,  which  is  regularly  posted  to  the  USENET   newsgroup
     rec.arts.startrek.tech.

OPTIONS
     -s[n]  Output the date as a stardate.  n, if given, specifies the number of
	    digits  output  after  the	decimal point.	If not specified, it de-
	    faults to 2.  The output looks like ``[i]nnnn.dd''.

	    When 2 decimal places are used,  the  output  of  the  current  time
	    changes  every  172.8 seconds.  (Actually, because of the resolution
	    of C time, four-fifths of the changes are 173 seconds after the pre-
	    vious change, and the other fifth are 172 seconds after.)

     -j     Output the date as a date in the Julian  calendar,	with  UTC  time.
	    The output looks like ``yyyy=mm=ddThh:mm:ss''.

     -g     Output  the date as a date in the Gregorian calendar, with UTC time.
	    The output looks like ``yyyy-mm-ddThh:mm:ss''.

     -q     Output the date as a date in the Quadcent calendar, with  UTC  time.
	    The output looks like ``yyyy*mm*ddThh:mm:ss''.

	    This  calendar  is explained in detail in the Stardates in Star Trek
	    FAQ.  Briefly, it uses seconds that  are  approximately  1.00066  SI
	    seconds  long, and has no leap years.  Each 400 years in this calen-
	    dar is exactly as long as 400 years in the Gregorian  calendar,  but
	    all years in the quadcent calendar are the same length.

     -u     Output the date in the form of the traditional Unix time.  This is a
	    number  of	seconds  since	midnight  UTC on 1970-01-01.  The output
	    looks like ``Unnnnnnnnn''.

     -x     Output the date in the form of the traditional Unix time,  in  hexa-
	    decimal.  The output looks like ``U0xnnnnnnnnn''.

INPUT FORMATS
     dates  may  be  specified in any of the output formats, as described above,
     with a few variations allowed.  More precisely,  the  following  forms  are
     permitted:

     [issue]nnnn
     [-issue]nnnn
     [issue]nnnn.dd
     [-issue]nnnn.dd
	    A  stardate.   The issue number, with the square brackets, is manda-
	    tory.  The fractional part is optional.

	    Stardate ``[0]0000.0'' is midnight UTC on 2162-01-04; negative issue
	    numbers indicate times before that.  If issue is less than	20,  the
	    number  must be in the range [0, 10000).  If equal to 20, [0, 5006).
	    If greater than 20, [0,  100000).	The  FAQ  explains  these  range
	    changes.

     yyyy=mm=dd
     yyyy=mm=ddThh:mm
     yyyy=mm=ddThh:mm:ss
	    A date in the Julian calendar, optionally with a time in UTC.

     yyyy-mm-dd
     yyyy-mm-ddThh:mm
     yyyy-mm-ddThh:mm:ss
	    A date in the Gregorian calendar, optionally with a time in UTC.

     yyyy*mm*dd
     yyyy*mm*ddThh:mm
     yyyy*mm*ddThh:mm:ss
	    A date in the Quadcent calendar, optionally with a time in UTC.

     Unnnnnnnnnn
     U-nnnnnnnnnn
     U0xnnnnnnnnnn
     U-0xnnnnnnnnnn
	    A Unix time specification - a number of seconds since 1970-01-01.  A
	    negative  number  indicates  a  time before 1970.  In the forms with
	    ``0x'', the number is in hexadecimal.

     Case of alphabetic characters in input is ignored.

AUTHOR
     Andrew Main <zefram@fysh.org>

SEE ALSO
     date(1), Stardates in Star Trek FAQ

BUGS
     This program will not handle dates BCE.

Stardates 1.6		9 February 1997, SD [-31]8857.62	     STARDATE(1)
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