Free/Busy feature on Zoho Calendar enables you to check if your invitees will be free to attend the event which you are hosting. On the Create Event window, click on Add Attendees link, and type the email addresses in the field provided. Click on the Free/Busy link beside the field to display the free and busy information of the invitees. If some users are busy at that time, you can also navigate to the next time slot to know when they will be free and schedule the event accordingly.