Calendar
Never miss an appointment with Calendar. Keep track of your busy schedule by creating multiple calendars, and manage them all in one place.
Create events. Click 
to add a new event, or double-click anywhere in a day. To invite someone, double-click the event, click the Add Invitees section, then type an email address. Calendar lets you know when your invitees reply.
See all your calendars—or just a few. Click the Calendars button to see a list of all your calendars; click the ones you want to see in the window.
Ask Siri. Say something like: “Set up a meeting with Mark at nine in the morning.”
A calendar for every part of your life. Create separate calendars—for example, for home, work, and school—each with its own color. Choose File > New Calendar to create a calendar, then secondary click (that is, right-click) each calendar to choose a new color.
Share across your devices and with others. When you’re signed in to iCloud, your calendars are kept up to date on all your Macs, iOS devices, iPadOS devices, and Apple Watch. You can also share calendars with other iCloud users.
Use the Touch Bar. Tap the Today button to view or edit today’s events, or use the slider to select the month—past or future.
Select an event in your calendar, and tap buttons to specify the calendar for the event, get event details, edit the time or place, and add or delete invitees.
Tip: If you add a location to an event, Calendar shows you a map, estimated travel time and time to leave, and even the weather forecast. Force click any event in Calendar to see more details.
Learn more. See the Calendar User Guide.