########################################################################
# MISC
########################################################################

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

Add the other ISO8601 stuff.

The only change needed to get it to work under 5.001 is to change the line:
   $file=cwd . "/$file"  if ($file !~ m|^/|);   # $file = "a/b/c"
to:
   $file=&getcwd . "/$file"  if ($file !~ m|^/|);   # $file = "a/b/c"
Since this also may eliminate a shell command (`pwd`), add a flag to
switch between the two.  Piran Montford <piran@cogapp.com>

Add 15/Oct/1997:07:56:43 (netscape log) suggested by:
 bugaj@dnrc.bell-labs.com  Stephan Vladimir Bugaj

Try to get rid of `date` in Date_TimeZone
Also, Cwd::cwd calls `pwd` (Bowen Dwelle) , but this may be inevitable.
If not, add a variable which will allow you to skip the sections where
   backticks are used since they are a performance sink.  Suggested by
   Bowen Dwelle.

Combine GetNext and GetPrev (?)

Add a "SPECIAL HOLIDAY" section to fully specify holidays so weird ones
can be defined for each year.  Add Easter calculations here as well:
  Easter = easter
means that Easter is calculated using the method easter.

Add
  Spanish
  German
  Italian
  Japanese (Kevin Baker will help)

Fill in some of the language variables ($past, $future, $zones).

Check Swedish/French special characters.

Change EXPORT to EXPORT_OK (message 9 by Peter Bray)

Add ParseDateTemplate where a template containing any of the formats
from UnixDate may be used in a string (which may contain perl REs)
to parse a very strange date.

########################################################################
# TESTS
########################################################################

Add tests for all the new ParseDate formats to the test suite.

########################################################################
# 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.

########################################################################
# DAYLIGHT SAVINGS TIME
########################################################################

Use POSIX tzset/tzname (and perhaps GNU date) to handle timezone and
daylight savings time correctly.  See messages by Marvin Soloman.

If ignoring TIMEZONE info, treat all dates as in current timezone with
no d.s.t. effects (i.e. Jun 1 12:00 EDT == Jun 1 12:00 EST).

To do calculations, convert to current timezone (Jun 1 12:00 EDT -> Jun 1
11:00 EST even if that date doesn't really exist)

Determine zone pairings EST/EDT, PST/PDT for all zones.  Store EST#EDT in
$Date::Manip::TZ rather than just EST or EDT.  Make sure everything is
paired up.  Places with only a single timezone should work as well.

Make a 2nd hash where EST -> EST#EDT for all timezones.

When doing date calculations, if neither date has a time (or if both are
at the exact same time and are in the same timezone or in timezones
related through daylight savings time such as EST and EDT), ignore the
time gain/loss from savings time transitions IFF the variable IgnoreDST
is on (it is by default).  Otherwise, do the calculation exactly.

Add an option to all date calculations to ignore daylight savings time
transitions.

########################################################################
# TIMEZONES
########################################################################

It is just too confusing knowing what timezone you are working it.  I
give up.  Change the internal format to YYYYMMDDHH:MN:SS+HHMN or
YYYYMMDDHH:MN::SS-HHMN
By default, convert all dates to current timezone however unless a
NOCONV option is set.

Add a Date_Compare to compare two dates (with timezone).

Modify all routines accordingly.

##SPEEDUPS

UpdateHolidays, don't use ParseDate to parse dates of form DD/MM or MM/DD.

In business mode date-date calculations, add a "quick" mode in which the
number of business days is estimated by:
    $date1 = &ParseDate("...");
    $date2 = &ParseDate("...");         # a 2nd date a long time after date1
    $delta = &DateCalc($date1,$date2);  # get an exact delta
    $days  = ( split(/:/,$delta) )[2];  # the number of days between the two
    $yrs   = $days/365.24;              # the number of years between the two
    $days  = $days*(5/7) - $yrs*9;
where 9 is the number of holidays in the year.  Add a variable to turn this
behavior off and another to tell what threshold to apply this to (by default
apply it to anything 2 months apart or more).  In this mode, only days are
returned, hours, minutes, seconds are ignored.

