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 - day of the week
12 - month names
13 - allow editting date or time without touching the other
14- [x] diagnose events failing to parse [[https://github.com/robur-coop/icalendar/issues/14]]
15- [x] [[https://github.com/robur-coop/icalendar/pull/13][handle RECURRENCE-ID]]
16- [x] [[https://github.com/robur-coop/icalendar/issues/15][RRULE with local datetime]]
17- [ ] CalDAV syncing
18 - Currently, you can use [[https://github.com/pimutils/vdirsyncer][vdirsyncer]]
19- [ ] support querying times as well as dates
20- [ ] custom date/time formatting
21- [ ] support querying regex
22- [ ] support VTIMEZONE
23- [ ] support VALARMS
24- [ ] support VOTODS
25- [ ] support VCARDS
26- [ ] server mode
27 - and maybe hold =Event='s in-memory instead of parsing them for every =Query=
28- [ ] implement TUI front end with something like [[https://github.com/leostera/minttea][minttea]]
29- [ ] implement an emacs front end, like mu4e to mu
30- [ ] parallel queries