TODO list for Perl module DateTime::Event::Recurrence

"ICAL FORMAT"

* tests with ICal format, using
  DateTime::Format::ICal->format_recurrence():
    wkst
    interval
    start date
    monthly, week + day (is it day-of-week or day-of-month?)

* it should not generate an ICal string 
  if it finds an invalid WKST or   # DONE
  if it specify nanoseconds or
  if there is a "start" value

* move class DateTime::Set::ICal to a separate file

OTHER

* move calculations to a DateTime::Util::* module

* add more tests with 'interval' > 1

* add more 'previous' tests

* find out how it behaves with mixed timezones and DST changes

* allow interleaved neg/positive values 
  See: t/11mixed_offset.t

    my $month = monthly DateTime::Event::Recurrence (
        days => [ -20, 20 ],
        minutes => [ 30 ] );

* remove repeated indexes
        days => [ 1 1 1 4 ],

* add more argument overflow tests:
  day in year, 
  week in year, 
  negative values, 
  ... 

