When setting up a task, you have the option to set reminders, which means that you don't even have to be logged into the system to find out what you need to do! The system can either send you an Email or an SMS for each reminder in order to nudge you to hurry up and complete that task!
So whether you are creating a new task or editing an existing task, the process is the same: by the 'Do you want to be reminded?' you can select whether by Email or SMS and set the time/date on which you wish to be reminded. You can set more than 1 reminder for each of your Tasks:
Once you have set your reminders, just click on 'Apply Changes'