Provide a name for the rule and select "Specific date and time".

Select event type
Activity viewed
Activity completed
Activity graded
User added to group
User removed from group
Course entered
Course grade change
Specific date and time
Recurring event
Quiz or assignment submitted
Forum reply
Forum topic post
Course start date

Adjust the Date to when you want the email to be sent out and click "Add" when you completed.

Select condition type
Activity viewed
Activity completed
Activity grade range
User role check
Group membership check
Course grade range
Course login
Date check

Select the "User role check" condition and set the following.

In the actions tab "Select the Send email" option and click "Add".

Adjust the send email parameters as follows. The first name should be changed as appropriate to the course.

In 'Recipients', click 'Add Recipient' for the 'To' field and select 'Triggering User'.

Type in an appropriate "Subject" to inform the students about the contents of the email.

Fill in the Body. This contains everything you wish to convey to the student. Feel free to use tokens to personalise the message.

Hi ((student_firstname)),

remember to submit your assignment!

Basic Scheduled Email