We can define reminders to be triggered before, after or at the time of the event, to the person whom the Task is assigned to.
To set reminders,
>> Go to Workflow through the left menu.
>> Go to Workflow Management.
>> Select the Workflow for which the reminders need to be set.
>> Choose a workflow instance> Select the Task for which reminder needs to be set.
=> Click on the bell icon next to a task to set one or multiple reminders.
>> Click on Reminders tab. Reminders can be set for Months, Hours, Days (working/calendar) or Weeks and can be selected to trigger Before, After or at the time of the Event.
Multiple reminders can be set for a Task.