In the Update Status section of the contact’s information is where you access the Calendar to set up an event, meeting or task related to this contact. In the image you see that you can choose the date and time and enter a reminder or message.
If you want to copy this to the contact, check the box at the arrow and they’ll receive an email. Then click Submit to record the item in your calendar.
You can find and view all calendar events for this contact using the Calendars button as here: