You can now schedule contacts to be subscribed to a campaign instead of subscribing them immediately. This means the first email of the campaign will go out at the scheduled subscription date & time.
To schedule a contact to be subscribed to a campaign at a future date, click on the clock icon to the right of the usual + / "Subscribe" button when editing subscribers of a campaign:
This will bring you to a screen that allows you pick the date & time that this contact will be subscribed. Once chosen, the first email of this particular campaign would not be sent until the scheduled time.
Once the contact is scheduled to be subscribed, the subscription status will change to Pending. If you hover over the clock, it will show the time that the contact is scheduled to be subscribed. You can update the scheduled subscription date by clicking the clock button again.
If you’d like to cancel the scheduled subscription, you can click the pending button to clear it. This simply removes the subscription schedule for that contact. It does not mark them as unsubscribed:
This schedule subscription functionality is also an option when subscribing all contacts, however, it is not yet available when subscribing groups.