I would like to define the hour to begin sending the second reminder mails or find a way to manually send them.
I explain: these mails need to include a key the owner of the site receives on midnight two days before the event (mandatory) and manually adds the key in the registrant form on morning. So I would like to begin to send these mails only after midday.
For example, the events beginning is the 27 march, the remaining mail is set two days before, so the mail will be sent on 25 march. But the keys will be received on 25 march 0:00 am, so it will be necessary to let some hours for adding these keys and not send the mails prematurely.