I know with real estates you have to drop what you're doing and attend to them immediately.
ie) you have your route planned out for the today. The real estate agent calls you to do some maintennace work on a home for showing purposes which is across the city which takes you 15mins to drive.
Do you a) drop everything and go? b) tell him you can't and you're sorry.
If you chose the latter option, the real estate will not go with you again in the future I pressume.