Task reminders can be set on any tasks that have been assigned to you.
You can set them in your My tasks dashboard - simply click on the Set reminder link (this is accompanied by a bell icon) and an off-canvas calendar will slide in from the right of the screen, just select the required date and it will be set and will replace the Set reminder link. Just click the date to remove or change.
You can also set the reminder from within the element that the task resides - just click on the bell icon in the toolset related to the task. Reminders can be set in either edit mode or not. When a reminder has been set, you will see the bell changes from an outline to a solid fill. Click the bell again to remove or change the reminder.
Your reminders will be email-delivered as part of your 7am daily summary and as an in-app notification.