TODO list for Perl module DateTime-Event-ICal

* "byday -2 friday"
  - use yearly;-1su to define 'wkst' !
  - test overflow
  - need some 'interval' and 'dtstart' tests

* the implementation of 'select' in Set::Infinite is incomplete
  and doesn't have the 'last' attribute. -- should be implemented!

* finish importing Date::Set RFC2445 recurrence tests

* wkst

* bysetpos
  - implement "previous" sub
  - use some kind of memoization
  - test overflow
  - optimize DateTime::Set "current" sub

* byweekno - test with 'daily'

* no tests were made defining recurrences without dtstart.

* the effect of 'count' on a recurrence without dtstart is not defined.
  the effect of count == 0 is not defined.

* no tests were made using datetimes with timezones.

* mixing positive and negative arguments in the same list
  might give wrong results is the numbers are big enough
  to cause the datetimes to interleave.

* some arguments are not checked for overflow,
  such as byyearday.

