The Wait by Attribute activity ensures that a contact receives your message at a specific time of day by holding the contact until the day and time value stored in their date-based attribute.
If the specified day and time passes before the contact reaches the wait activity, or if the attribute value is missing, the contact immediately proceeds to the next activity. If you enable the configuration to extend the wait duration until a specific time, the contact is held in the wait activity. Even if the original configured time has passed, the contact waits until the next occurrence of that specific time.
When the date-based attribute for a contact equals May 1, 2025 and the contact reaches the Wait by Attribute activity on May 5, 2025, the contact is released from the wait at 1:00 AM Indiana GMT-5:00 on May 6, 2025. The date-based attribute date of May 1, 2025 plus one day is May 2, 2025. Since today is May 5, 2025, the contact is released to the next activity. However, since the marketer added the configuration to extend the wait until 1:00 AM, the contact waits until the next occurrence of 1:00 AM Indiana GMT-5:00.