If there is a break in data, Facebook replays can be implemented for a maximum of 7 days of historical data. Facebook's
event_time can be up to 7 days before you send an event to Facebook. If any
event_time in data is greater than 7 days in the past, Facebook will return an error for the entire request and not process the event.
This is a FB limitation and not a Segment one, as their API would reject any event older than 7 days.