Send E-Mails after a customized time

Hello all,
after participants have taken part in my survey, I would like to send you an email with a reminder for the second part of the survey. This should happen after exactly 48 hours. With the email trigger function in the survey, setting 48 hours was not possible, but it was possible with the E-Mail Task in the workflows. So I created a task that sends an email to my participants after 2 days. However, I would like to remind the participants a second time six hours after the first email (54 hours after participation in the study). Unfortunately, I cannot find a function for this, as I can only select numbers up to 30. Is there a solution for this? Thank you very much in advance!