Airline pilot work hours are strictly governed by safety regulations like the FAA (US) and EASA (Europe) to prevent fatigue. A pilot's "Flight Duty Period" (FDP), which includes pre-flight briefings and ground duties, typically ranges from 9 to 14 hours per day. The exact limit depends on factors like the time they reported for duty and the number of flight segments they are flying; starting at 4:00 AM for four short flights allows for less duty time than starting at 10:00 AM for one long flight. For long-haul international trips with "augmented crews" (3 or 4 pilots), the duty day can extend up to 17 to 19 hours if the aircraft has designated crew bunks for rest. After a duty day, pilots are legally required to have a minimum rest period, usually at least 10 to 12 hours, before they can fly again.