Office 365 (Outlook 2013 / 2016 for Win) - Create an Appointment
In Outlook, appointments aren’t the same as meetings. Appointments are activities that you schedule in your calendar that don’t involve inviting other people or reserving resources, such a conference room. ***NOTE - In Outlook 2016, icons have replaced the words as per the second image below.
In Calendar, click New Appointment. You can also right-click a time block in your calendar grid, and then click New Appointment.