Command-line and Emacs Calendar Client
1- [x] list/search events
2- [x] add/remove events
3- [x] edit events
4- [x] timezones
5- [x] remove collection module
6 - ref [[https://github.com/ocaml-ppx/ppxlib/issues/481]] cc patrick
7- [ ] allow editing recurrence-ids
8- [ ] don't load all calendars into memory to show only one event
9- [ ] support specifying duration
10- [ ] better add/edit event datetime parsing
11- [x] diagnose events failing to parse [[https://github.com/robur-coop/icalendar/issues/14]]
12- [x] [[https://github.com/robur-coop/icalendar/pull/13][handle RECURRENCE-ID]]
13- [x] [[https://github.com/robur-coop/icalendar/issues/15][RRULE with local datetime]]
14- [ ] CalDAV syncing
15 - Currently, you can use [[https://github.com/pimutils/vdirsyncer][vdirsyncer]]
16- [ ] support querying times as well as dates
17- [ ] custom date/time formatting
18- [ ] support querying regex
19- [ ] support VTIMEZONE
20- [ ] support VALARMS
21- [ ] support VOTODS
22- [ ] support VCARDS
23- [ ] server mode
24 - and maybe hold =Event='s in-memory instead of parsing them for every =Query=
25- [ ] implement TUI front end with something like [[https://github.com/leostera/minttea][minttea]]
26- [ ] implement an emacs front end, like mu4e to mu
27- [ ] parallel queries