In general, I use vdirsync to sync my contacts and calendars locally, keeping the remote system's values to resolve conflicts as I intend to only read the values from the CLI. Vdirsync uses an application-agnostic format, so I could in theory read from any application that supports standard file formats:
$ cat ~/.vdirsyncer/config
[general]
status_path = "~/.vdirsyncer/status/"
# Contacts
[storage contacts_personal_local]
type = "filesystem"
path = "~/.vdirsyncer/contacts/"
fileext = ".vcf"
[storage contacts_personal_remote]
type = "carddav"
url = "https://example.com/remote.php/carddav/"
username = "bloodninja"
password = "hunter2"
[pair contacts_personal]
a = "contacts_personal_local"
b = "contacts_personal_remote"
collections = ["from a", "from b"]
conflict_resolution = "b wins"
# Calendars
[storage calendar_personal_local]
type = "filesystem"
path = "~/.vdirsyncer/calendars/"
fileext = ".ics"
[storage calendar_personal_remote]
type = "caldav"
url = "https://example.com/remote.php/caldav/"
username = "bloodninja"
password = "hunter2"
[pair calendars_personal]
a = "calendar_personal_local"
b = "calendar_personal_remote"
collections = ["from a", "from b"]
conflict_resolution = "b wins"
metadata = ["color"]
Then I set up khal to read from the directory that vdirsync stores data in, and display three months with events and use the ISO-8601 date format:
$ cat ~/.config/khal/config
[calendars]
[[personal]]
path = ~/.vdirsyncer/calendars/*
type = discover
[default]
default_calendar = personal
highlight_event_days = True
timedelta = 45d
[locale]
firstweekday = 6
timeformat = %H:%M
dateformat = %Y-%m-%d
longdateformat = %Y-%m-%d
datetimeformat = %Y-%m-%d %H:%M
longdatetimeformat = %Y-%m-%d %H:%M
default_timezone = Asia/Jerusalem
unicode_symbols = False
[highlight_days]
color = light green
method = fg
If you have any questions or suggestions I'll be watching this thread.