With AwesomeShare function, user can easily send or receive an item(note, event and reminder) to other people. But when you need to share all events belonging to a calendar, NOT a single item, it is not enough. Moreover you may want to automatically share your items, as soon as you add a new one.
You may have several calendars in your ios device. For example, work, home, school, and so forth. You can share a certain calendar among those with other people.
If you and your friends turn on iCloud for iCal, your can share your calendar with giving access-permission to him. Refer to following link to know in detail.
Second option is Google calendar.If you and your friends use google calendar, visit google calendar website and give permission to him. You can find instructions at below link.