Can I plan mailings in advance?

Yes, you can schedule send out of your mailing.

To do so you need to create new mailing and choose Schedule here:

When you choose day and time (remember you can also change the time zone), click on Schedule.

You will be redirected to the mailings list, where you can find all your mailings scheduled mailings with the following icons:

If you need to edit anything in your scheduled mailing you can do it by clicking the pen icon here

When you implement all the changes you need in your mailing you need to schedule it again because it changes its status to draft.