########################################################################
# +1 significant release
########################################################################

Add support for doing calculations which ignore daylight-saving time
transitions (so 1 day is 1 day, NOT 24 hours).

   Date::Manip::Delta

      new()
         $self{'calendar'} = undef    (not set explicitly)
                             0/1      (se explicitly)

      parse($string [$mode,$mode,...])

         If $mode is 'calendar', the delta is treated as groups:
            (y,m) (w,d) (h,mn,s)
            (y,m) (w) (d) (h,mn,s)    if business delta
         If $mode is 'business' (or any other non-null value), it's a
         business mode delta.

         There is no word that can be added to the delta to make
         it parsed as a calendar delta.

      set('business',$val)
      set('normal',$val)
         Deprecated
      set('mode','calendar')
         Set the calendar mode.
      set('delta',[Y,M,W,D,H,MN,S,MODE1,MODE2,...])

      type($op)
         $op can be 'business', 'normal', 'exact', 'calendar'

   Date::Manip::Calc

      (date,date, [$subtract] [$mode,$mode,...])
      (date,delta [$subtract] [$mode,$mode,...])
         $mode can be 'exact', 'approx', 'business', 'calendar'
         Deprecate 'bapprox'

         A calendar mode delta ignores daylight saving time issues
         mostly.  Add 1 day and the time stays the same (and in the
         same timezone) (if possible).  If that isn't possible, it
         adds 24 hours

      (delta,delta)
         The two deltas must be the same type exactly

   Date::Manip::Config

      CalendarMode
         If set to true, all calculations default to calendar mode
         if $self{'calendar'} is undef.


See if I can get Date::Manip to use a different YAML module (which doesn't use
Module::Build) if YAML::Syck is not available.  Based on discussion with Martin
Zinser.

Add UseTZ
  = %all      use all timezones
  = %local    use local timezone
  = Z1 Z2 ... use zones Z1, Z2, etc. (one can be %local)
Only affects parsing.

Add ways to get timezone in cygwin

Cache Date::Manip::TZ::zone for ($abbrev,isdst), ($abbrev,$isdst,$offset),
other???

Profile it and look for optimizations.

Date::Manip::Base : get rid of
   _calc_date_time_strings
   _delta_convert

Benchmarks
   Modules
      5.x
      6.00
      6.00 parse_format
      DateCalc
      TimeDate
      ???
   Tests
      10,000 dates (parse)                          time + size
      10,000 dates (parse + 2 adds + 1 unix date)   time + size
      10,000 scripts (parse 1 date + 2 adds + 1 unix date each) time

Rewrite Problems.pod (Date Manip is slow)

Clear out all problems from CPAN

Methods which require a valid object (secs_since_1970_GMT) should exit
instead of trying to perform the operation if the object is invalid.
RT #60662 (Matt Blythe)

########################################################################
# +2 significant release
########################################################################

Switch to YAML::XS (but it converts text to non-UTF-8 so take that into account)

Everywhere a timezone can be entered, allow:
   zone
   abbrev
   offset
followed by an option:
   std       either STD or DST time, test STD first (default always)
   dst       either STD or DST time, test DST first
   stdonly   only test STD
   dstonly   only test DST

Change Date::Manip::Base so that $date input can be reference or
string.

Clear as much of the backlog of suggestions as possible.

#### Recur

Add ParseRecur flag:
   WDn (n=1-7): Day n of the current week.

Add a new flag:
  IBD  = is business day
If the current date (with all previous flags applied) is a business
day, keep it, otherwise discard this date.

########################################################################
# TO DO
########################################################################

Add support for parsing:
  Thu Jan 21 17:13:27 2010 -0400
(which means that the time and timezone are NOT next to each other).

Make sure there is a correspondance between:
  time,localtime,gmtime
  Date_SecsSince1970,Date_SecsSince1970GMT
  UnixDate(...,"%s"),UnixDate(...,"%u")
and document it all.

Support timezones of the format +500.  David Coppit

Make sure that &DateCalc($date1,"") returns an error.  Jim Anderson

Add a function for printing "words" from the language.  For example:
  printf_value("%b",2) => Feb
  printf_value("%b")   => (Jan Feb ...)
Chris Jackson

Mark Dedlow
  nth DAY of month

Change the Jan1Week1 variable to accept the values "m1-m7" (1st week contains
Jan X) or "d1-d7" (1st week contains the 1st dX day of week ... so d1
means that the 1st week of the year contains the 1st Monday).

Free up the '%u', '%h', and '%X' printf formats. Reserve '%X' for
  extended formats (%Xa, %Xb, ...).

########################################################################
# TO CONSIDER
########################################################################

Add a method:
   ($date0,$date1) = $date->week_range();
where $date0 and $date1 are the start and end of the week containing
$date.  Ha Quach

Add support for partial dates (John Washburn)
   April 1625 == April 1, 1625

Add Date_LocaleInit which calls Date_Init and then sets DateFormat
config varialbe.  Benjamin Low
   Essentially, I use POSIX::strftime to print a known date in the locale
   'native' format ('%x'), and parse the result to determine d/m/y, m/d/y,
   or y/m/d.
   
   Here's what I do for Date::Parse, perhaps for your module you could just
   substitute a default value for DateFormat:
   
   sub _dmorder
   # determine the "natural" day/month order for the current locale
   # - returns a sub which will expect two arguments (month, day) and
   #   return the arguments swapped as appropriate
   {  
	# %x - preferred (year, month, day) representation
	# - some examples: 1999-12-31, 31/12/99, 30.12.1999, 12/31/99
	my @d = (POSIX::strftime('%x', 0, 0, 0, 31, 12-1, 99) =~ 
		/(\d+)\D+(\d+)\D+(\d+)/);

	# check we got one each of "31", "12", and "[19]99" back
	$@ = "couldn't determine day,month order (got [@d])";
	warn("$@\n"), return sub { @_ } unless @d == 3;
	my %d;	$d{$1} = $d{$2} = $d{$3} = 1;
	warn("$@\n"), return sub { @_ } 
		unless ($d{31} and $d{12} and ($d{99} or $d{1999}));

	if ($1 == 31) { $@ = undef; return sub { ($_[1], $_[0]) } };	# d/m/y
	if ($2 == 31) { $@ = undef; return sub { ($_[0], $_[1]) } };	# m/d/y
	if ($3 == 31) { $@ = undef; return sub { ($_[0], $_[1]) } };	# y/m/d

	return sub { @_ };	# undetermined, use default
   }
   
   *dmorder = _dmorder();
   
   # and then later in Parse::Date, after month/day regexps (\d+/\d+)...
     - ($month, $day) = ($1, $2);    becomes...
     + ($month, $day) = dmorder($1, $2);


Make DateFormat variable handle y/m/d y/d/m m/d/y and d/m/y formats
in addition to m/d vs. d/m .  Also, make "%D" and "%x" UnixDate formats
use this variable.  Benjamin Low

Use of holidays and other named days in ParseDate ("Christmas 1995")
Abigal

Make the following work for ParseDate Adrian Conte:
  1 epoch
  epoch 1
  -1 epoch
  epoch -1

Add another INIT variable to NOT initialize any language variable unless
needed.

Make work weeks able to start and stop on arbitrary days (even across
weekends).  Mohammed Saggaf

Switch to Math::BigInt instead of using "no integer".  Vishal Bhatia

Use autoloader.  Ted Ashton

Change EXPORT to EXPORT_OK. Peter Bray

Better support for fractional seconds.  RT 61535

########################################################################
# GRANULARITY
########################################################################

$flag=&Date_GranularityTest($date,$base,$granularity [,$flags] [$width])
   $date and $base are dates
   $granularity and $width are deltas
   $flags is a list of flags

   To test if a day is one of every other Friday (starting at Friday
   Feb 7, 1997), go:
      $base=&ParseDate("Friday Feb 7 1997");
      $date=&ParseDate("...");
      $granularity=&ParseDateDelta("+ 2 weeks");
      $flag=&Date_Granularity($date,$base,$granularity,"exact");
   If $flag is 1, the $date is a 2nd Friday from Feb 7.

   The most important field in $granularity is the last non-zero element.
   In the above example, 2 weeks returns the delta 0:0:14:0:0:0 so the
   last non-zero element is days with a value of 14.

   If $flags is empty, $date is checked to see if it occurs some multiple
   of 14 days before or after $base.  In this case, hourse, minutes, and
   seconds are completely ignored.

   If $flags contains the words "before" or "after", $date must come
   before or after $base.

   If $flags contains any other options, or if $width is passed in, the
   test is treated in an approximate way.  A flag of "approx" forces this
   behavior.

   If $width is not passed in in an approximate comparison, it defaults
   to 1 in the last non-zero element.  Here, the default width is 1 day.
   If the flag "half" is used, the width (default or passed in) is
   halved.

   For example if $width is 1 day, add a multiple of $granularity to
   $base to get as close to $date as possible.  If $date is within plus
   or minus 1 day of this new base, the test is successful.  A flag of
   "plus" or "minus" means that $date must be with plus 1 day or within
   minus one day of this new base.  Flags of "before" or "after" work
   as well.

@list=&Date_GranularityList($date,$N,$granularity)
   Returns a list of $N dates AFTER $date which are created by adding
   $granularity to $date $N times.  If $N<0, it returns $N dates BEFORE
   $date (the list is in chronological order).

   Make it work in business mode as well which will return only working
   days.  Example, every other friday and it can be told that if friday
   falls on a holiday to return either thursday or the following monday
   or leave it out.
