When generating an itinerary from a Booking, the toggle for Use Assignment Items controls whether or not to use the Start Time and/or End Time of the Cost Item assigned to a Guest rather than the Start Time and/or End Time of the Cost. For example, there are two time slots for an excursion on day 2 and Cost Items have been setup to record those two time slots. If all of the Guests on the itinerary have been assigned to the 9am time slot, then the Start Time for that Cost will display as 9am in their itinerary when the toggle is on. If some of the Guests on the itinerary have been assigned to the 9am time slot and others to the 10am time slot, then the Cost will appear twice in the itinerary.
NOTE: No changes are required to Itinerary Templates to take advantage of this feature but you may want to consider updating your templates to include a list of Guests next to each Cost so that your Guests know which of them are booked on which time slot. For more details see
NOTE: This feature is only supported when generating itineraries from a Booking