Keep everyone in your group informed about upcoming events. Here’s how to create an iCloud calendar and share it with others.

How to share an iCloud calendar on iPhone, iPad, and iPod touch | Apple Support

You can share an iCloud calendar with others so they can view, add, and change events. Here's how. In the Calendar app, tap Calendars at the bottom of the screen. Make sure Calendars is turned on in your iCloud settings if it isn't one already. Tap the Info button next to the calendar you want to share, then tap Add Person. Choose who to share with, then tap Add. Everyone you invite needs to use iCloud for calendars. When someone receives a shared calendar invite, they can tap Inbox, then tap Join Calendar to add it.