########################################################################
##
## Copyright (C) 2000-2024 The Octave Project Developers
##
## See the file COPYRIGHT.md in the top-level directory of this
## distribution or <https://octave.org/copyright/>.
##
## This file is part of Octave.
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## Octave is free software: you can redistribute it and/or modify it
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## -*- texinfo -*-
## @deftypefn {} {t =} now ()
## Return the current local date/time as a serial day number
## (@pxref{XREFdatenum,,@code{datenum}}).
##
## The integral part, @code{floor (now)} corresponds to the number of days
## between today and Jan 1, 0000.
##
## The fractional part, @code{rem (now, 1)} corresponds to the current time.
## @seealso{clock, date, datenum}
## @end deftypefn

function t = now ()

  t = datenum (clock ());

  ## The following doesn't work (e.g., one hour off on 2005-10-04):
  ##
  ##   seconds since 1970-1-1 corrected by seconds from GMT to local time
  ##   divided by 86400 sec/day plus day num for 1970-1-1
  ##   t = (time - mktime(gmtime(0)))/86400 + 719529;
  ##
  ## mktime (gmtime (0)) does indeed return the offset from Greenwich to the
  ## local time zone, but we need to account for daylight saving time
  ## changing by an hour the offset from CUT for part of the year.

endfunction


%!assert (isnumeric (now ()))
%!assert (now () > 0)
%!assert (now () <= now ())