Apple Calendar is Apple's built-in calendar app. Together with iCloud, it keeps your schedule up to date across your devices, according to Apple, and lets you share events with friends and family. The app is installed on Apple devices, while synchronisation and storage run through Apple's iCloud service.
Apple Inc. is headquartered in Cupertino, United States. For users in the EEA, the United Kingdom and Switzerland, Apple Distribution International Limited in Ireland is the data controller. According to its privacy policy, data collected worldwide is generally stored by Apple Inc. in the United States, and transfers from the EEA are covered by standard contractual clauses. The iCloud terms state that content is stored on servers of Apple or of third-party providers. A specific storage location for calendar data is not documented. A European organisation using Apple Calendar for business is therefore exposed to US law, such as the CLOUD Act, and should make its own assessment.