Hey @DanP,

If you haven’t already, I would recommend reviewing our How date-based flows schedule recipients Help Center article.

The scenario you mentioned is actually explained in the What happens when a date is updated in the middle of a flow section of it:

What happens when a date is updated in the middle of a flow

Before every action in a flow (e.g., before every email or SMS that goes out), Klaviyo verifies that the date used to trigger the flow is still the same. This means that if someone is in a date-based flow but changes the date such that it falls outside the flow’s timeline, they will not be sent any further messages.

For instance, say that Jane from the example above is in the middle of a wedding flow.

Originally, her wedding date is 5/1/2021 and she just passed the “Wait until 7 Months before person's Wedding” point and received the associated message. If she changes her date to 6/1/2023, she will exit the flow and not receive the subsequent messages at this time.

Klaviyo will also automatically reschedule the person based on the updated date. This is particularly helpful for appointment-focused flows — if someone's appointment is rescheduled, all messages are automatically rescheduled around the new date.

For the case above, Jane will automatically re-enter the flow from the beginning when her new wedding date approaches. This may mean she receives the same messages twice; however, this is a good thing, as the content will be personalized to where she is currently in wedding planning and she won’t need to comb through her emails for the previous messages.

In essence, by default, if someone updates the their date property while going through a flow, they would be removed from it. 

David