A text-based calendar and scheduling application for the command-line. More information: https://github.com/lfos/calcurse/blob/pu/doc/calcurse.1.txt.
calcurse on interactive mode:calcurse
calcurse {{[-a|--appointment]}}
calcurse-caldav --init=keep-remote
calcurse-caldav --init=keep-local
calcurse-caldav --init=two-way