Figure: Use Outlook appointments to easily synchronise your calendar with your client's This way Outlook will remind your colleagues about the appointment and you can update them if any changes are made.
If the appointment is for 3 days or less, send a separate appointment for each day. This is because multiple-day appointments appear at the top in your Outlook Calendar, so you risk missing the appointment (see below).
Figure: Bad Example - Multiple-day appointments appear hidden at the top of your Outlook calendar, so you might miss it, thinking that the time is free 
Figure: Good Example - Send a separate appointment for each day so you can clearly see it in your Outlook calendar