Each of these should be moved to a subtask of this issue.
Add extra features:
Improved input widgets
Allow minimum and maximum alternative options: relative to now, relative precreate intervals.
More granularities:
year-week
year-month-week
year-month-day-hour,
year-month-day-minute
Support operators: Configure less than end date, or more than start date. Current implementations matches on intersecting, within, or encompassing occurrences..
