CalDAV
Calendar Distributed Authoring and Versioning (CalDAV) is a network protocol used for synchronizing calendars between devices and applications that support them. It allows for the exchange of calendar data via WebDAV/HTTP and, therefore, access the user’s calendar and synchronization from any device, whether it is a computer, a smartphone or a tablet.
Thus, when appointments, events or time slots are managed or edited on a given device, the changes are made automatically on all synchronized devices.