All jobs are scheduled for 2 hour arrival windows. A job scheduled for 2-4 means that the technician is scheduled to arrive between 2-4. If a customer calls in asking when their technician will be there, give them the scheduled arrival window and advise them that their technician will call once on their way.
If the customer calls toward the end of or after their scheduled arrival, message the chat to see if the technician is running behind. If you do not get a quick response, let the customer know that the tech may be running behind, and they will receive a call shortly with an ETA. Create a ticket and collect the best number to call back at.