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 * add tests for error-messages * 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