It is very common to prepare a message that you will not send immediately, but on a specific day and time.
You will be able to choose date and time to send your campaign. Also you have the option to schedule considering each contact's timezone.
After that you will have the option to cancel and edit the campaign. In case you'd like to send it instantly or change the date and time:
You may also be interested in knowing when is a good moment to send the campaign.