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STARDATE(1)            DragonFly 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 stardates.  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
       (currently) (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 accepted as input.  The only exception is for dates
       within the first half second of the acceptable range, where the value
       output in the quadcent calendar, ``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 defaults 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 previous 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 calendar 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
              hexadecimal.  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
              mandatory.  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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