Every Sapling Learning activity with a deadline can be set up as an event in your device's iOS calendar, which will send you an alert 48 hours before the deadline. To change the time of an alert, simply click on the event in your device's iOS calendar and change the alert time option.
To receive the alerts across your iOS devices and OS X systems (e.g. MacBook Pro, MacBook Air), enable iCloud on each device or system. Go to iOS Settings, then iCloud and create an account or log in.
Android users can create calendar events in the Google Calendar app.
The app will prompt you to set up a default notification for all assignments. You can then adjust individual calendar events from within the Google Calendar app.
For more information, please read the help article How do I change the time that an alert notifies me?.