What is the Reminders calendar for?
Use the Reminders Calendar to keep track of birthdays, work anniversaries and other important dates related to your users and assets. Birthdays and work anniversaries are displayed here by default, other dates you want to keep track of are uploaded here from custom fields.
To do this, just create a custom field of type Reminder. Important reminders might include, for example, the Medical Examination Validity Date, the Asset service date, or the End of Trial Period.
All upcoming reminders can also be found clearly in the Reminders report, which can be clicked directly from the calendar.