Apple Calendar

Apple Calendar does what a calendar should do without trying to be more. It syncs across iCloud, Google Calendar, and any CalDAV source, so work and personal events show up in the same place without manual effort. The week view on desktop is clean and the iPhone widget keeps the next few events visible at a glance.

I've looked at alternatives but the integration with the rest of the Apple ecosystem makes it hard to justify switching. Event notifications, Siri awareness, and Shortcuts support all work because the calendar is part of the platform, not bolted on.