Google Classroom. But the problem was that you would then have to go back and post them when you wanted students to see the posts. Beginning today that is no longer the case. About an hour ago Google announced that you can now schedule assignments, announcements, and polls to appear at a later time in your Google Classroom stream.
To schedule an assignment in Google Classroom simply select the scheduling option when you're drafting an assignment. You can pick the day and time at which you want your assignment to be visible to your students.
Applications for Education
The scheduling option in Google Classroom could be used in much the same way that I have used scheduled blog posts over the years. Rather than having to post an assignment or quiz on the morning that you need students to see it, you can write and schedule things in advance.
Join my online course to learn how to get the most out of Google Apps for Education. You can earn three graduate credits through the course.