A red-eye flight is a flight that departs late at night (usually after 9:00 PM) and arrives at its destination early the next morning (typically before 6:00 AM). The term comes from the physical side effect of travelers having tired, bloodshot eyes due to the lack of a full night's sleep in a proper bed. These flights are most common for eastward travel across time zones, such as flying from Los Angeles to New York or London to Dubai, where the time difference "shortens" the night. Red-eye tickets are popular for two main reasons: they are often cheaper than daytime flights, and they allow travelers (especially business professionals) to "save a day" by arriving in the morning ready for work without paying for an extra night's hotel stay. However, the downside is significant fatigue and jet lag the following day, as sleeping in an airplane seat—even in Premium Economy—rarely provides the same level of restorative rest as a standard bed.