You can schedule your formative to open and close on designated days and at designated times!
Within a formative:
Select "Assign" at the top of the page
Select your class
Click "Adjust settings (optional)" underneath your class list
Click the toggle next to "Schedule open/closed times"
Here you can select the date and time you would like your formative to open and close. Next, click "Assign & Post to Google" (For Google Classroom) or "Assign".
Your Formative assignment will appear as a draft assignment until the scheduled open time, at which point it will appear as an assignment on your Classwork page!
Please note: It can take up to five minutes after the schedule time for the assignment to appear in Google Classroom.